Nn        ..^ 


MODERN    SCIENCE   AND 
MATERIALISM 


BY  THE  SAME  AUTHOR 

Modern  Science  and  the  Illusions  of 
Professor  Bergson 

With  Preface  by  SIR  RAY  LANKESTER,  K.C.B., 
F.R.S.,  etc.  Crown  8vo.  6s.  net. 

Letters  of  John  Stuart  Mill 

Edited,  with  an  Introduction,  by  HUGH  S.  R. 
ELLIOT.  With  a  Note  on  Mill's  Private  Life 
by  MARY  TAYLOR.  With  6  Portraits.  2  vols. 
8vo.  21  s.  net. 

LONGMANS,  GREEN  AND  CO. 

London,  New  York,  Bombay,  Calcutta,  and  Madras. 

Lamarck's  Zoological  Philosophy 

Translated,  with  an  Introduction,  by  HUGH 
ELLIOT. 

MACMILLAN   AND   CO.,   LTD. 


MAKERS  OF  THE  NINETEENTH  CENTURA 

Herbert  Spencer 

By  HUGH  ELLIOT. 

CONSTABLE  AND  CO.,  LTD. 


MODERN  SCIENCE  AND 
MATERIALISM 


BY 

HUGH    ELLIOT 


LONGMANS,    GREEN   AND   GO. 

39    PATERNOSTER    ROW,    LONDON 

FOURTH  AVENUE  &  30TH  STREET,  NEW  YORK 

BOMBAY,    CALCUTTA,    AND   MADRAS 

1919 


Made  in  Great  Britain 


PREFACE 

THE  preparation  of  this  book  has  involved  a  study  of 
many  different  branches  of  Science  and  Philosophy.  As  I 
completed  my  survey  of  these  various  branches  in  turn,  I 
usually  summed  up  the  conclusions  which  I  had  gathered 
and  published  them  as  articles  in  the  reviews,  with  the 
object  partly  of  giving  precision  to  the  ideas,  partly  ot 
gaining  the  advantage  of  criticism.  It  thus  comes  about 
that  I  have  to  make  a  number  of  acknowledgments  for 
permission  accorded  me  to  republish  parts  of  these  articles 
in  the  present  work.  The  greater  part  of  Chapter  I  was 
published  in  the  Candid  Quarterly  Review  for  November  1916. 
Certain  portions  of  Chapter  III  appeared  in  the  Edinburgh 
Review  for  January  1909,  January  1911,  and  April  1912. 
Part  of  Chapter  IV  was  published  in  Science  Progress  for 
January  1915.  The  theory  of  Chapter  V  was  sketched  in 
two  articles  in  the  Hibbert  Journal  in  April  and  July  1916. 
Finally,  a  ^small  part  of  Chapter  VI,  and  many  of  the  ideas 
of  Chapter  IV,  were  developed  in  articles  in  (Bedrock  in 
October  1912,  July  1913,  and  January  1914.  To  the  pro- 
prietors of  these  Reviews  I  tender  my  cordial  thanks  for 
their  courtesy  in  allowing  me  to  make  use  of  these  articles 
for  the  present  work. 

I  have  also  to  thank  Mr.  Mark  Barr  for  many  valuable 
observations  and  criticisms  on  Chapter  II. 

H.  E. 


CONTENTS 

CHAP.  PAOB 

INTRODUCTION 1 

I.    THE  UNIVERSE  AS  A  WHOLE       ....  18 

II.    MATTER  AND  ENERGY 40 

III.  LIFE  AND  CONSCIOUSNESS 71 

IV.  THE  FALLACY  OF  VITALISM           ....  104 
V.    MATERIALISM 132 

VI.    IDEALISM  .  174 


MODERN  SCIENCE  AND 
MATERIALISM 

INTRODUCTION 

IN  all  ages  since  the  dawn  of  civilization,  inquiring  minds 
have  been  enthralled  by  certain  fundamental  questions, 
which  are  felt  to  be  of  greater  magnitude  and  importance 
than  any  of  those  matters  of  detail  which  confront  us  in 
the  ordinary  course  of  our  daily  lives.  What  are  we? 
whence  have  we  come  ?  whither  are  we  going  ?  what  was  the 
object  of  the  Universe  ?  and  what  will  be  its  end,  if  it  ever 
have  an  end  ? — questions  such  as  these  have  oppressed  all  the 
greatest  thinkers  of  history ;  they  have  perplexed  to  some 
extent  nearly  all  men,  save  those  whose  mental  horizon  is 
limited  to  the  immediate  satisfaction  of  their  material 
wants. 

Yet,  after  more  than  two  thousand  years  of  civilization, 
not  one  of  these  questions  has  advanced  in  the  smallest 
degree  towards  a  solution.  There  has,  indeed,  been  no 
lack  of  speculation  or  of  theories  which  for  a  time  were 
believed  to  be  solutions.  Innumerable  systems  of  mythology, 
systems  of  religion,  systems  of  philosophy,  innumerable 
superstitions,  too  crude  and  incomplete  to  be  called  systems, 
have  risen  at  different  times  and  places,  have  secured  the 
allegiance  of  tribes,  nations,  and  races,  have  risen  and 
flourished  for  a  time,  then  crumbled  away  and  lost  all 
interest  except  to  the  archaeologist  and  historian.  The 
greatest  and  most  learned  minds  in  the  annals  of  mankind 
B 


2      MODERN  SCIENCE  AND  MATERIALISM 

have  worn  themselves  out  over  these  problems,  and  still 
made  no  step  towards  an  answer.  Yet  they  continue  to 
weigh  upon  thoughtful  minds  with  undiminished  force. 
Moreover,  there  is  a  general  recognition  of  their  funda- 
mental importance  for  humanity.  Religion  occupies  a 
pre-eminent  position  in  human  affairs.  It  is  regarded  as 
apart  from  and  above  other  things.  This  fact  alone  is 
sufficient  evidence  how  deeply  the  human  mind  is  impressed 
by  the  ultimate  mysteries  of  existence. 

Although  the  desire  for  knowledge  of  this  kind  is  so 
imperative  in  man's  nature,  all  attempts  to  satisfy  it  have 
failed.  It  is  clear  at  the  outset,  therefore,  that  the  subject 
itself  is  outside  the  range  of  human  intellect.  If  a  solution 
ever  could  have  been  found,  it  would  assuredly  have  been 
found  before  now.  Philosophy  cannot  furnish  answers  to 
these  ultimate  questions ;  it  can,  however,  do  something 
towards  allaying  unsatisfied  curiosity,  partly  by  making  clear 
what  branches  of  inquiry  are  necessarily  outside  the  scop& 
of  human  intellect,  partly  by  setting  forth  the  things  that  we 
can  know  in  an  organized  and  systematic  form.  Philosophy 
can  do  no  more  than  this :  mark  off  the  sphere  of  possible 
knowledge  from  the  sphere  where  knowledge  is  impossible ; 
then  collect  together  the  main  principles  that  emerge  in  the 
knowledge  at  present  possessed  by  mankind ;  and  thereby 
we  shall,  at  all  events,  perceive  to  the  highest  extent  possible 
where  it  is  that  we  stand  in  Nature,  and  what  is  the  general 
aspect  of  the  Universe. 

Let  us  first  ask  why  it  is  that  all  past  efforts  to  solve 
ultimate  riddles  have  failed,  and  why  it  is  that  they  must 
continue  to  fail.  It  is,  in  the  first  place,  due  to  the  fact 
that  all  knowledge  is  based  on  sense-impressions,  and  cannot, 
therefore,  go  beyond  what  the  senses  can  perceive.  Men 
have  five  or  six  different  senses  only,  and  these  are  all  founded 
on  the  one  original  sense  of  touch.  Of  these  five  or  six 
senses,  the  three  of  most  importance  for  the  accumulation 
of  knowledge  are  those  of  sight,  hearing,  and  touch.  By 


INTRODUCTION  3 

these  senses  we  are  able  to  detect  three  separate  qualities 
of  the  external  Universe.  Now,  supposing  that  we  happened 
to  have  a  thousand  senses  instead  of  five,  it  is  clear 
that  our  conception  of  the  Universe  would  be  extremely 
different  from  what  it  now  is.  We  cannot  assume  that  the 
Universe  has  only  five  qualities  because  we  have  only  five 
senses.  We  must  assume,  on  the  contrary,  that  the  number 
of  its  qualities  may  be  infinite,  and  that  the  more  senses 
we  had,  the  more  we  should  discover  about  it. 

Not  only  are  our  senses  few,  but  they  are  extremely 
limited  in  their  range.  The  sense  of  sight  can  detect 
nothing  but  waves  in  aether ;  all  sensations  of  light  and 
colour  are  no  more  than  aethereal  waves  striking  upon  the 
retina  with  varying  strength  and  frequency.  And  even  then, 
it  is  only  special  aethereal  undulations  that  give  rise  to  the 
sensation  of  sight.  The  majority  cannot  be  perceived  by 
the  retina  at  all ;  it  is  only  when  the  waves  follow  one 
another  within  certain  limits  of  rapidity  (between  four 
hundred  billion  and  seven  hundred  billion  a  second)  that 
sight  ensues.  If  the  waves  are  below  the  lower  limit  of 
rapidity,  they  do  not  give  rise  to  the  sensation  of  light  at  all, 
though  they  may  give  rise  to  a  sensation  of  heat.  If  they  are 
more  rapid  than  the  higher  limit  (as  in  the  case  of  ultra- 
violet rays)  they  are  not  discernible  by  any  sense  at  all. 

The  sense  of  sound,  similarly,  is  caused  by  vibrations  of 
the  air ;  but  if  the  vibrations  pass  a  certain  limit  of  rapidity 
(about  thirty-eight  thousand  a  second)  nothing  whatever  is 
heard.  In  the  same  way,  the  sense  of  touch  cannot  detect  a 
very  light  contact,  and  is  crushed  by  a  very  heavy  one.  All 
the  senses  thus  operate  only  within  a  very  narrow  range ;  that 
upon  which  we  most  rely — namely,  sight — tells  us  nothing 
more  than  the  existence  of  certain  waves  in  aether  following 
one  another  at  certain  intervals,  and  this  small  piece  of 
knowledge  is  surely  next  to  nothing,  when  we  are 
endeavouring  to  understand  the  ultimate  realities  of  life  and 
existence. 


4      MODERN  SCIENCE  AND  MATERIALISM 

Thus  all  our  knowledge  of  the  Universe  is  based  on  sense- 
impressions  ;  nor  can  we  so  much  as  imagine  or  conceive  of 
anything  that  is  beyond  the  sphere  of  our  senses.  We  can, 
indeed,  become  aware  of  many  things  outside  the  range  of 
sense  by  means  of  reasoning.  We  cannot  see  that  the  Earth 
is  spherical,  but  we  can  infer  it.  The  aether  of  space 
makes  no  impression  on  our  senses,  and  its  more  rapid 
vibrations  cannot  be  perceived.  Yet  we  can  easily 
understand  that  they  exist,  and  in  our  "  mind's  eye "  see 
the  ultra-violet  rays  which  our  bodily  eye  is  blind  to. 
We  are  still  working  in  terms  of  vision,  even  though  it  is 
imaginative  and  not  actual  vision.  The  same  truth  applies 
to  our  most  transcendental  efforts  of  imagination.  Take,  for 
instance,  the  religious  conception  of  an  after-life.  If  we 
imagine  it  at  all,  it  must  be  in  terms  of  sense-impression, 
otherwise  nothing  remains:  if  we  exclude  sense-impression 
we  have  nothing  but  total  darkness,  total  silence,  total  - 
anaesthesia,  no  taste,  smell,  or  pressure,  no  feeling  of  motion. 
Yet  we  do  not  conceive  of  an  after-life  in  this  manner, 
as  though  we  should  be  blind,  deaf,  and  paralyzed.  We 
conceive  of  it,  if  at  all,  in  terms  of  light,  sound,  motion, 
however  vaguely.  Even  here  our  imaginations  are  limited 
by  the  range  of  our  present  senses. 

If,  then,  all  knowledge  and  all  imagination  is  based  on 
sense-irnpressions,  it  is  clear  that  our  notion  of  the  Universe 
is  bound  to  remain  for  ever  of  the  most  incomplete  possible 
character.  Supposing  we  had  a  few  more  senses,  how  very 
different  everything  would  appear !  Supposing  we  had  a 
hundred  more  or  a  thousand  more,  the  Universe  must  appear 
different  from  anything  now  conceivable.  To  a  being  thus 
endowed,  the  philosophy  of  a  mere  human  being  must  appear 
indeed  primitive.  His  understanding  would  exceed  ours  by 
far  more  than  ours  exceeds  that  of  a  sea-anemone  washed 
by  the  waves  and  drawing  within  its  tentacles  whatever 
edible  morsel  happens  to  float  by.  Yet,  though  it  would 
so  vastly  exceed  ours,  the  intellect  of  even  this  being  would 


INTRODUCTION  5 

be  no  nearer  than  we  are  to  the  ultimate  mysteries  of 
existence.  For  if  the  Universe  cannot  be  understood  by  one 
who  perceives  only  five  or  six  of  its  modes  of  working,  we 
can  hardly  suppose  that  its  secrets  would  be  delivered  up 
if  we  knew  a  hundred  or  a  thousand  of  its  modes.  A  still 
more  exalted  being,  possessing  a  million  senses,  would  far 
surpass  one  with  a  thousand  ;  but  to  understand  the  ultimate 
nature  of  the  Universe,  we  should  require  not  a  thousand, 
nor  a  million  senses,  not  a  finite  number  of  senses  at  all, 
but  an  infinite  number ;  for  so  long  as  we  have  anything 
less  than  an  infinite  number  of  senses,  there  must  always 
remain  unknown  aspects  of  the  Universe,  which  might  be 
disclosed  by  the  possession  of  further  senses.  It  follows 
plainly  enough  that  ultimate  mysteries  are  not  soluble  by 
us,  and  that  attempts  to  solve  them  arise  only  from  a 
total  misconception  of  the  nature  of  the  problems  at  issue 
We  are  forced  at  the  outset  to  adopt  the  position  of 
Agnosticism. 

Let  us  be  clear  what  we  mean  by  this  name  of  Agnosti- 
cism, for  the  word  has  been  bandied  about  so  much  in  public 
controversy  that,  as  generally  occurs  with  words  in  common 
use,  its  meaning  has  become  vague  and  ill-defined.  Last 
century  it  was  employed  largely  as  the  converse  of  theism. 
In  opposition  to  those  who  affirmed  the  existence  of  a  God, 
there  arose  a  school,  calling  themselves  Agnostics,  who, 
without  denying  this  existence,  took  the  view  that  it  was 
impossible  to  say  whether  or  not  a  God  exists.  This  school, 
moreover,  was  apt  to  assume  that  Agnosticism  was  the  final 
goal  of  philosophy,  and  thereafter  that  nothing  more  remained 
to  be  said.  The  Agnosticism  of  this  school  is  very  different 
from  that  which  we  are  now  about  to  adopt.  In  the  first 
place,  it  is  far  more  limited  in  scope.  The  question  of  the 
existence  or  non-existence  of  a  God  is  an  isolated  single 
question,  to  which  the  new  Agnosticism  pays  little  attention, 
and  which  it  even  repudiates  altogether.  For  it  is  not 
necessarily  an  unanswerable  question ;  it  is,  perhaps,  even 


6      MODERN  SCIENCE  AND  MATERIALISM 

relatively  easy  to  answer.  The  earlier  Agnostics  themselves 
very  often  answered  it  by  implication,  for  their  general 
attitude  was  such  as  to  suggest  a  definite  disbelief  in  the 
existence  of  a  God.  The  new  Agnosticism  does  not  touch 
this  particular  question ;  it  refers  only  to  the  impossibility 
of  reaching  any  solution  of  ultimate  mysteries  by  any  theory 
whatsoever. 

Still  more  incorrect  is  it  to  regard  Agnosticism  as  the 
final  goal  of  philosophy.  So  far  from  being  the  end,  it  is 
the  actual  beginning  of  knowledge.  We  have  to  start  with 
it  as  an  axiom  ;  and,  having  studied  it,  and  recognized  all 
its  implications,  we  have  to  go  on  and  establish  our  philosophy 
afresh  within  the  limits  set  by  our  initial  Agnosticism.  The 
discovery  of  Agnosticism — the  discovery  of  our  ignorance, 
that  is  to  say — though  not  the  end  of  philosophy,  is  a  most 
important  landmark  in  the  history  of  philosophy.  The 
position  prior  to  this  discovery  was,  not  only  that  men  were 
ignorant,  but  that  they  were  ignorant  of  their  own  ignorance. 
They  knew  no  more  than  we  do  what  is  the  ultimate  origin 
or  destiny  of  the  Universe,  but  they  thought  they  knew; 
indeed,  so  certain  were  they  of  their  own  knowledge,  that 
they  have  often  meted  out  abuse  and  persecution  to  those 
who  questioned  it.  For,  be  it  noted,  a  conscious  belief  in 
one's  own  ignorance  implies  a  considerable  advance  of 
civilization.  The  original  state  of  man  was  one  of  the  most 
violent  and  irrational  convictions.  The  belief  in  after-life 
was  so  implicit,  that  women  would  cast  themselves  on  their 
husband's  funeral  pyre  to  rejoin  them  immediately  after 
death ;  that  money-lenders  would  advance  money  on  note 
of  hand  payable  in  the  next  world.  As  civilization  progresses, 
the  intensity  of  irrational  conviction  declines,  while  the 
intensity  of  rational  conviction  correspondingly  increases. 
Knowledge  grows  and  pseudo -knowledge  dwindles,  till  men 
begin  to  question  the  basis  of  their  beliefs,  and  finally 
formulate  the  theory  of  Agnosticism  to  destroy  the  last 
remnants  of  pseudo-knowledge  or  superstition.  Agnosticism 


INTRODUCTION  7 

is  thus  a  clearance  of  the  mental  rubbish  handed  down  to 
us  from  the  past,  and  preserved  by  the  infirmity  of  our  own 
minds.  The  era  of  Agnosticism  marks  the  point  in  the 
history  of  philosophy  at  which  our  minds  are  swept  clean, 
and  rendered  suitable  repositories  for  genuine  knowledge. 
The  mental  progress  of  mankind  is  thus  not  from  conviction 
to  scepticism  or  vice  versa.  The  beginning  and  the  end  of 
progress  are  equally  characterized  by  strong  conviction.  At 
the  beginning  it  is  the  conviction  of  bigotry  and  superstition  ; 
at  the  end  it  is  the  conviction  of  science.  Between  these 
two  termini  the  bridge  of  Agnosticism  has  necessarily  to  be 
traversed — the  great  discovery  by  mankind  of  their  own 
ignorance  in  presence  of  the  immeasurable  complexity  of 
their  environment. 

It  is  not  the  purpose  of  the  present  work  to  furnish  a 
defence  of  the  Agnostic  position.  That  task  was  sufficiently 
carried  out  by  the  writers  of  last  century,  and  in  my  work 
Modern  Science  and  the  Illusions  of  Professor  Bergson  I 
said  all  that  seemed  necessary  in  destruction  of  metaphysical 
pseudo-knowledge.  The  purpose  of  the  present  book  is  not 
destructive  but  constructive.  If  we  take  our  start  from 
Agnosticism,  it  means  no  more  than  that  we  embark  on 
our  inquiries  with  minds  free  from  the  encumbrance  of 
superstition.  We  start  then,  as  every  scientific  investigation 
ought  to  be  started,  from  an  Agnostic  position ;  and  the 
first  question  that  arises  is,  what  kind  of  philosophy  we  can 
construct  within  the  limits  drawn  for  us  by  Agnosticism. 
In  other  words,  what  sort  of  philosophy  can  be  founded  on 
the  present  knowledge  attained  by  man  ?  Naturally  such  a 
philosophy  must  be  far  less  ambitious  than  the  metaphysics 
of  those  who  are  not  bound  to  the  solid  earth,  but  are  free 
to  soar  wherever  their  imagination  can  penetrate.  Our 
philosophy,  on  the  other  hand,  must  be  strictly  based  on 
facts,  and  capable  of  verification  by  direct  observation  or 
experiment.  Its  progress  is  wholly  dependent  on  the  know- 
ledge of  the  times.  As  that  knowledge  increases,  true 


8      MODERN  SCIENCE  AND  MATERIALISM 

philosophy  can  likewise  expand ;  and  in  times  of  ignorance 
no  true  philosophy  is  possible.  We  have  expressly  abandoned 
all  attempts  to  understand  the  ultimate  nature  of  things ; 
nevertheless,  the  present  state  of  human  knowledge  is 
sufficient  to  permit  the  emergence  of  certain  fundamental 
principles  of  profound  philosophic  import.  It  is  the  purpose 
of  the  present  book  to  collect  together  and  present  these 
all-embracing  principles,  and  to  show  that  they  constitute 
on  the  one  hand  a  materialistic  system,  and  on  the  other 
hand  an  idealistic  system,  according  to  which  way  we  look 
at  them,  and  to  whether  we  employ  the  objective  or  the 
subjective  method. 

Since  our  philosophy  is  to  be  built  upon  facts — upon  the 
knowledge  possessed  by  men  at  the  present  time — the  first 
task  of  this  book  must  be  to  review  that  knowledge,  not, 
of  course,  with  any  thought  of  exhaustiveness,  but  in  order 
to  indicate  the  general  scope  and  nature  of  the  facts  known 
to  mankind,  upon  which  philosophy  must  necessarily  be 
based.  A  philosophic  principle  is  one  that  embraces  a  vast 
multitude  of  facts ;  moreover,  such  a  principle  is  immedi- 
ately upset  by  the  discovery  of  any  single  fact  which  con- 
flicts with  it.  It  is  true,  no  doubt,  that  most  of  the  great 
generalizations  of  science,  such,  for  instance,  as  the  Law  of 
Gravitation  1  and  the  first  two  Laws  of  Thermodynamics, 
are  so  solidly  established  that  the  discovery  of  any  contra- 
dictory fact  is  scarcely  conceivable.  Any  such  alleged 
discovery  would  suggest  only  error  or  illusion  on  the  part 
of  the  discoverer.  Thus  it  happens  that  these  great  prin- 
ciples, which  may  rightly  be  called  philosophic,  are  based 
upon  a  stronger  foundation  of  certainty  than  any  single 
fact  can  claim.  They  are  based  on  long  and  universal 
experience,  which  confers  upon  them  as  high  a  degree  of 
certainty  as  can  be  attained  by  humanity. 

1  Without  prejudice  to  the  Principle  of  Relativity.  As  to  how  far 
Newton's  Laws  may  be  an  absolute  and  final  expression  of  the  facts,  is  a 
question  I  do  not  raise. 


INTRODUCTION  9 

Now  human  knowledge  is  systematized  and  embodied 
under  the  name  of  science.  To  science,  therefore,  we  must 
look  as  the  foundation  of  our  philosophy.  But  science 
as  a  whole  is  divided  up  into  a  number  of  separate  sciences, 
each  of  which  is  studied  by  a  different  kind  of  worker. 
This  division  is  made  for  the  practical  convenience  of  study  ; 
it  does  not  correspond  to  any  actual  divisions  of  natural 
phenomena.  Nature  is  a  whole,  not  broken  up  into  separate 
compartments ;  and  to  obtain  a  true  idea  of  the  knowledge 
of  our  times,  we  must  disregard  the  limits  of  the  special 
sciences,  and  survey  Nature  as  a  whole ;  thus  only  can  we 
know  where  modern  knowledge  has  carried  us  in  helping 
us  to  perceive  where  we  now  stand  with  reference  to  the 
great  problems  of  philosophy. 

In  making  such  a  survey,  our  outlook  is  indeed  very 
different  from  that  of  the  common  man  who  sees  around 
him  only  those  things  which  have  an  immediate  interest 
for  himself.  We,  on  the  other  hand,  must  suppress  our  own 
individuality,  and  look  at  Nature,  not  as  though  we  our- 
selves were  the  centre  of  it,  but  as  it  has  been  disclosed  by 
the  culture  of  the  various  sciences:  we  must  look  at  Nature 
from  the  utterly  disinterested  standpoint  of  an  outside 
observer,  and  with  an  eye  of  transcendent  power ;  for 
this  philosophic  eye  is  served  on  the  one  hand  with  the 
most  powerful  telescopes  of  astronomy,  and  on  the  other 
hand  with  the  most  powerful  microscopes  of  modern  science. 
We  are  thus  no  longer  limited  to  seeing  objects  of  a  size 
commensurable  with  ours ;  our  range  of  vision  is  mightily 
extended,  and  the  things  which  we  shall  see  are  vastly 
different  from  those  which  appear  to  the  unaided  and  self- 
centred  vision  of  the  common  man. 

When  we  thus  look  out  on  Nature  with  a  philosophic 
eye,  what  is  it  that  we  behold  ?  The  Universe  is  made 
up  of  vast  aggregates  of  matter,  moving  about  in  various 
directions,  emitting  light  and  heat,  and  displaying  other 
physical  manifestations.  Nothing,  we  notice,  appears  to  be 


10    MODERN  SCIENCE  AND  MATERIALISM 

still ;  while  we  look,  there  is  no  single  particle  of  matter 
that  has  remained  in  the  same  position  with  regard  to  other 
particles,  nor,  out  of  the  great  aggregates  of  matter  com- 
posing the  various  stars  and  nebulae,  is  there  any  which 
remains  even  for  a  moment  just  exactly  what  or  where  it  was. 
In  other  words,  we  see  that  all  things  are  in  a  state  of 
change  or  flux  ;  nothing  remains  unaltered  for  an  instant.  It 
is  a  moving  and  changing  Universe  with  which  we  have 
to  do. 

In  the  next  place,  all  that  we  behold  may,  as  a  first  step,  be 
classified  into  two  or  three  categories  of  phenomena.  Firstly 
(pending  further  analysis),  there  is  what  we  call  matter.  This 
comprises  all  the  objects  which  we  discern.  Then  there  are 
motion,  heat,  light,  sound,  electricity,  etc.,  etc.,  which  are 
not  matter,  but  which  are  all  related  to  one  another,  and 
constitute  one  fundamental  phenomenon  ;  this  we  call  energy. 
As  we  look  further,  we  may  think  we  see  a  third  type  of 
manifestation,  which  cannot  be  brought  under  the  heading  of 
either  matter  or  energy.  This  third  type  we  call  life  and 
mind.  As  regards  life,  indeed,  we  perceive  it  only  on  one 
insignificant  portion  of  matter,  namely,  the  Earth ;  and  our 
eye  is  not  yet  sufficiently  developed  to  inform  us  by  direct 
vision  whether  it  occurs  elsewhere.  As  regards  mind,  we  are 
still  more  circumscribed,  for  we  know  it  directly  only  in  our 
own  person,  and  the  perception  of  it  elsewhere  is  no  more 
than  a  matter  of  inference. 

Leaving  aside  for  the  moment  this  third  category  of 
life  and  mind,  we  find,  then,  that  the  Universe  con- 
sists of  matter  and  energy  in  a  state  of  permanent  change. 
We  perceive,  moreover,  that  the  whole  course  of  that 
change  is  not  haphazard,  but  that  it  follows  certain  fixed 
sequences — usually  called  laws — which  are  so  definite  that 
even  in  the  present  state  of  knowledge  many  future 
events  can  be  prophesied  with  certainty;  and  that,  if  our 
knowledge  was  unlimited,  all  future  events  could  be  so 
prophesied. 


INTRODUCTION  11 

All  human  knowledge  is  derived  by  observation  and 
experiment.  The  facts  thus  made  known  are  co-ordinated 
or  systematized  in  the  various  sciences.  They  are  the  indi- 
vidual bricks  out  of  which  the  edifice  of  a  scientific  theory  is 
built.  As  isolated  facts,  they  have  little  philosophic  import ; 
but  in  proportion  as  they  can  be  co-ordinated  into  broad 
generalizations,  they  take  on  a  deeper  philosophic  signifi- 
cance. Science,  therefore,  alone  can  furnish  the  data  of 
philosophy.  If  there  is  any  knowledge  attainable  that  can 
truly  be  called  philosophic,  it  is  such  knowledge  only  as 
is  yielded  by  a  study  of  the  various  sciences.  Consequently, 
the  first  thing  to  be  done  in  any  search  after  philosophic 
principles  is  to  travel  over  the  special  sciences  with  a  view 
to  extracting  from  them  such  information  as  is  relevant  to 
our  purpose. 

Stated  differently,  the  problems  usually  comprised  under 
the  name  of  philosophy  are  those  dealing  with  the  great 
questions  of  profound  human  interest :  what  is  man's  place 
in  the  Universe  ?  whether  there  is  any  transcendental  purpose 
inherent  in  the  eternal  drifting  of  matter  and  energy  ?  and  so 
on.  The  answer — in  so  far  as  any  answer  is  possible — to 
these  ultimate  questions  must  plainly  be  reached  by  marshal- 
ling together  such  information  as  we  already  possess  con- 
cerning the  Universe.  The  primitive  mind  has  a  small 
knowledge  of  real  facts,  and  upon  this  narrow  basis  erects 
a  vast  fabric  of  mythology  or  ontology.  The  more  developed 
mind  has  a  larger  knowledge  of  real  facts ;  and  upon  this 
broader  basis  erects  a  far  less  ambitious  superstructure  of 
philosophy.  Before  we  can  discern  the  deeper  relationships 
of  existence  and  the  Universe,  we  must  know  all  that  can  be 
known  about  these  ultimate  facts.  That  is  a  task  far  tran- 
scending the  powers  of  any  single  mind ;  nevertheless,  if  we 
limit  our  endeavour  to  the  establishment  of  a  few  general 
principles,  it  does  become  possible  to  test  them  by  application 
to  the  different  branches  of  natural  science.  We  must,  then, 
begin  by  reviewing  the  scientific  knowledge  of  our  times — 


12    MODERN  SCIENCE  AND  MATERIALISM 

not,  of  course,  with  the  smallest  pretension  to  completeness/ 
— but  with  a  view  to  extracting  all  such  information  as  bears 
upon  the  principles  we  propose  to  establish.  The  first  four 
chapters  of  this  book  are  devoted  to  that  task  ;  the  two  final 
chapters  endeavour  to  present  the  philosophical  conclusions 
that  emerge  from  this  study. 

Chapter  I  deals  with  the  material  structure  of  the  Universe, 
in  so  far  as  it  can  be  seen  by  powerful  telescopes  or  inferred 
from  observations  made  with  such  telescopes.  We  clearly 
have  to  begin  with  some  account  of  the  general  distribution 
of  matter  throughout  the  Universe  on  the  largest  imaginable 
scale. 

Chapter  II  deals  with  the  constitution  of  matter  itself,  and 
some  of  the  main  laws  of  matter  and  energy.  The  magni- 
tudes we  have  here  to  deal  with  are  infinitely  small — small 
beyond  the  wildest  dreams  of  fancy.  From  these  two  chap- 
ters alone  we  already  get  a  broader  basis  for  philosophic 
generalization.  The  first  deals  with  magnitudes  so  great  as 
to  be  for  ever  beyond  the  remotest  possibility  of  imagination ; 
the  second  with  magnitudes  so  small  as  equally  to  defy  the 
most  transcendent  powers  of  description. 

Chapter  III  deals  with  life  and  consciousness,  in  which  the 
magnitudes  are  those  recognized  in  our  ordinary  life.  But 
we  find  that  in  another  way  the  strain  upon  our  imagination 
rivals  that  to  which  we  are  subjected  in  the  spheres  of 
Astronomy  and  of  Physics.  It  is  no  longer  by  magnitude 
that  we  are  oppressed  and  baffled.  It  is  by  complexity  and 
variability.  For  there  is  no  dividing  line  between  organic 
and  inorganic.  A  living  plant  or  animal  is  a  portion  of 
matter  with  contained  energy,  in  no  way  different  in  principle 
from  an  inorganic  compound.  The  difference  merely  lies  in 
the  inconceivable  complexity  of  its  constitution.  Here, 
therefore,  we  are  introduced  to  a  third  sphere,  in  which  the 
truths  of  Nature  transcend  to  an  infinite  extent  the  most 
boundless  imagination.  It  is  hard  to  say  in  which  sphere 
we  are  most  completely  paralyzed — whether  in  the  con  tern- 


INTRODUCTION  13 

plation  of  infinite  greatness,  or  of  infinite  smallness,  or  of 
infinite  complexity. 

Nevertheless,  we  have  already  greatly  enlarged  our  outlook 
upon  Nature.  The  Universe  is  wonderfully  different  from 
that  little  world  in  which  we  pass  our  commonplace  lives. 
In  whatever  direction  we  look  out,  we  are  quickly  carried 
away  beyond  the  bounds  of  our  feeble  imaginative  faculties. 
And  if,  in  whatever  direction  we  look,  and  however  far  we 
go,  we  find  the  same  principles  at  work  everywhere,  then  we 
are  justified  in  stating  those  principles  as  the  elements  of 
philosophic  truth.  We  can  find  no  more  ;  they  are  the  limit 
of  what  a  man  can  know. 

Chapter  IV  deals  with  the  relation  of  consciousness  to  the 
nervous  system,  and  is  a  prelude  to  the  general  discussion  in 
Chapter  VI  as  to  the  relations  of  mind  and  matter.  For  all 
thought  and  all  intellect  appear  to  us  as  mental  in  texture, 
by  strong  contrast  to  things  that  are  material  in  texture. 
Yet  the  process  of  conscious  life  within  the  organism  is 
altogether  dependent  on  the  material  processes  occurring 
within  its  brain  and  nervous  system.  In  any  discussion  as 
to  the  nature  of  mind,  the  first  thing  to  be  done,  therefore, 
is  to  collect  together  every  shred  of  information  furnished  by 
physiology  as  to  the  general  trend  of  the  nervous  pheno- 
mena underlying  consciousness.  Woefully  incomplete  as  our 
information  still  remains,  certain  large  truths  do  emerge ;  and 
they  are  sufficient  for  our  purpose.  Physiology  has  already 
attained  results  of  cardinal  importance  to  philosophy.  We 
must  hold  fast  to  that  solid  rock  in  entering  the  dangerous 
quagmire  of  metaphysics ;  and  if  we  do,  we  shall  find  we  do 
not  sink.  In  treating  subjects  hitherto  relegated  to  meta- 
physics, we  have  at  length  this  immovable  rock  established 
by  physiology.  If  we  anchor  ourselves  firmly  to  it,  and 
accept  whatever  conclusions  we  are  thereby  forced  to  accept, 
we  shall  indeed  come  across  much  that  is  startling  and 
unfamiliar — much  that  disconcerts  all  our  habitual  modes  of 
thought — but  we  shall  at  length  reach  a  positive  conclusion 


14    MODERN  SCIENCE  AND  MATERIALISM 

from  which  all  the  old  paradoxes  have  fallen  away,  a  conclu- 
sion which  must  be  true,  if  our  physiological  basis  is  sound. 
For,  although  so  many  of  the  older  problems  of  metaphysics 
are  insoluble,  the  relation  of  mind  and  matter  is  not  insoluble. 
I  venture  to  think  that  its  solution  is  contained  within  the 
later  advances  of  physiology. 

Chapters  V  and  VI  describe  the  main  principles  of  mate- 
rialism, which  appear  to  emerge  from  the  preceding  review 
of  scientific  conclusions.  Those  conclusions  seem  to  me  to 
•  lead  to  a  most  uncompromising  and  complete  materialism  ; 
but  they  also  lead  to  a  no  less  uncompromising  idealism.  In 
short,  the  old  antithesis  between  materialism  and  idealism 
vanishes  completely.  They  are  not  two  rival  doctrines  ;  but 
^  they  are  one  and  the  same  doctrine,  looked  at  from  different 
aspects  and  stated  in  different  words.  So  long  as  mankind 
are  a  prey  to  the  dualistic  superstition — the  belief  that  mind 
and  matter  are  two  fundamentally  different  things — so  long 
will  the  two  rival  philosophic  doctrines  remain  reared  up  in 
antagonism  against  each  other.  But  once  the  position  of 
monism  is  accepted,  the  antagonism  falls  away.  There  are 
no  longer  two  fundamentally  different  things  ;  and  no  longer 
will  there  be  two  opposed  philosophic  theories  as  to  their 
nature. 

I  have  approached  the  subject  from  the  point  of  view  of 
materialism,  not  because  I  regard  it  as  any  truer  than  ideal- 
ism, but  because  it  is  a  far  more  fertile  aspect  from  which  to 
view  the  facts.  Idealism  enunciates  a  single  truth,  which 
goes  no  further  and  leaves  nothing  more  to  be  said. 
Materialism  enunciates  the  same  truth  in  different  lan- 
guage ;  but  that  is  only  the  beginning :  it  leads  much 
further ;  in  fact  it  leads  everywhere  that  the  human  intellect 
can  reach  ;  it  lies  at  the  basis  of  science,  of  history,  of 
human  activities. 

The  theory  of  Chapter  VI  appears  to  come  near  to  the 
views  which  Mr.  Bertrand  Russell  has  reached  by  the  methods 
of  pure  logic  alone.  At  all  events,  I  have  often  been  aston- 


INTRODUCTION  15 

ished  to  find  in  his  works  conclusions  so  harmonious  with 
those  deducible  from  physiological  principles,  and  yet  attained 
by  sheer  force  of  reasoning  from  altogether  different  data. 
But  in  other  respects  the  conclusions  of  this  book  are  very 
different  from  those  of  Mr.  Russell. 

The  theory  is  in  a  much  closer  accordance  with  the  Radical 
Empiricism  of  William  James ;  but  James  again  reached  it 
by  metaphysical  means.  Moreover,  he  took  the  view  that  it 
was  allied  to  indeterminism,  theism,  etc.,  and  opposed  to 
Agnosticism  and  scientific  naturalism  or  positivism — a  view 
very  difficult  to  understand,  since  my  one  reason  for  believing 
in  it  is  that  it  is  the  only  theory  compatible  with  physio- 
logical mechanism.  Once  the  dualistic  theory  of  epiphe- 
nomenalism  is  abandoned — as  it  is  now  abandoned  on  all 
sides — there  remains  no  alternative  whatever  but  to  accept 
Radical  Monism,  unless,  indeed,  we  are  prepared  to  admit 
the  hypothesis  of  Vitalism,  which  is  entirely  opposed  to 
physiological  principles.  James  did,  in  fact,  much  against 
his  will,  recognize  the  materialistic  implications  of  his 
doctrine.  He  remarks :  "  I  greatly  grieve  that  to  many  it 
will  sound  materialistic."  It  sounds  materialistic  because 
it  is  plain  materialism,  though  why  that  should  be  a  cause 
of  grief  I  do  not  understand.  The  essence  of  the  theory  is 
that  there  are  not  two  different  things, "  mind  "  and  "  matter," 
but  one  thing,  "pure  experience,"  which  takes  the  form  of 
psychical  or  physical  according  to  its  associations.  To  James, 
it  was  a  theory  of  epistemology ;  to  me,  it  is  a  theory  of 
physiological  psychology.  "  Philosophers,11  he  writes,  "  have 
constructed  the  entity  known  to  them  as  consciousness.  That 
entity  is  fictitious  .  .  .  thoughts  in^the  concrete  are  made  of 
the  same  stuff  as  things  are."  No  materialist  could  wish  for 
more ;  and  yet  is  it  not  just  what  idealists  have  always  said 
from  the  time  of  Berkeley  onwards  ?  The  old  antithesis  has 
vanished. 

This  book  is  published  at  a  time  when  there  is  much  talk 
of  "reconstruction."  The  need  for  reconstruction  is  plain 


16    MODERN  SCIENCE  AND  MATERIALISM 

enough  in  industry ;  but  it  is  still  more  urgent  in  the  realm 
of  ideas.  Let  us  reconstruct  our  ideas  in  accordance  with 
the  truths  of  external  nature.  Once  we  get  into  true  habits 
of  thought,  the  rest  will  flow  from  it  without  any  special 
contrivance.  Nothing  can  be  more  palpably  false  than  the 
system  of  ideas  now  reigning  throughout  civilization.  The 
Church  for  two  thousand  years  has  dominated  opinion :  and 
see  the  result.  If  humanity  ever  learnt  by  experience,  they 
would  assuredly  hasten  to  the  most  extreme  form  of  material- 
ism they  could  find.  For  things  are  not  what  they  seem  to 
be  on  the  surface.  Christianity  does  not  lead  to  an  age 
of  universal  brotherly  love,  as  we  might  expect  from  its 
doctrines  ;  nor  does  materialism  lead  to  any  of  the  alarming 
consequences  which  its  numerous  enemies  endeavour  to 
anticipate. 

There  are  many  who  think  they  can  get  on  very  well  with- 
out any  kind  of  philosophy.  But  philosophy  is  no  more 
than  a  name  for  our  general  outlook  upon  the  world.  Every 
one  has  a  philosophy  of  some  sort,  however  little  they  may 
be  conscious  of  it.  Such  ideas  as  men  possess  are  governed 
and  directed  by  their  general  mode  of  thought,  and  the  man 
who  truly  has  no  philosophy  is  a  man  whose  head  is  empty 
of  ideas.  All  that  is  urged  in  the  present  work  is  that  we 
should  fashion  our  ideas  in  conformity  with  what  we  know  of 
external  Nature,  and  not  according  to  the  precepts  of  any 
artificial  system.  Let  us  look  boldly  at  things  as  they  are ; 
let  us  cease  fabricating  our  beliefs  in  accordance  with  what 
we  desire  to  believe,  and  let  us  believe  only  what  we  perceive 
to  be  true.  No  man  can  have  a  true  philosophy,  unless  he 
has  discarded  much  that  he  would  have  preferred  to  keep 
and  accepted  much  that  he  would  have  preferred  to  reject. 
There  is  often  bitterness  in  truth.  He  who  does  not  know  it 
is  as  yet  undisciplined,  and  may  be  sure  that  his  philosophy 
is  false.  For  the  bitterness  is  in  Nature  itself;  truth  is  quite 
independent  of  our  personal  predilections.  So  long  as  we 
admit  error  into  our  philosophy,  our  actions  will  accordingly 


INTRODUCTION  17 

be  wrong.  The  bitterness  has  to  be ;  better  that  it  should 
be  experienced  in  the  realm  of  thought  than  in  that  of  action. 
For  when  once  we  have  acquired  true  habits  of  thought 
the  fight  is  over;  true  modes  of  conduct  and  activity  flow 
inevitably  from  them. 


CHAPTER   I 

THE    UNIVERSE    AS    A    WHOLE 

As  we  look  at  the  skies  on  Ta  starry  night,  we  cannot  help 
asking  ourselves  questions  about  the  nature  of  the  Stellar 
Universe,  of  which  we  form  so  insignificant  a  part.  What 
is  the  distance  of  these  stars?  What  is  the  condition  of 
them  ?  Do  any  of  them  support  life  such  as  we  know  it  ? 
And,  furthermore,  do  they  continue  to  be  scattered  at 
intervals  to  the  most  remote  depths  of  space;  or  is  the 
Stellar  Universe  a  mere  island  situated  in  the  midst  of 
infinite  void  ? 

Modern  researches  in  stellar  Astronomy  have  begun  to 
suggest  answers  to  some  of  these  questions,  which  not  many 
years  ago  were  shrouded  in  the  blackest  veil  of  mystery.  It 
is  still  true  that  precise  answers  are^  usually  not  available  ; 
and  such  answers  as  can  be  given  are  frequently  dependent 
on  speculations  which  leave  considerable  latitude  for  error. 
Science  abhors  speculation  :  it  confines  itself  only  to  those 
facts  which  can  be  ascertained  by  the  (often)  laborious 
processes  of  observation  and  experiment,  and  to  a  certain 
number  of  cautious  deductions  from  them — deductions 
which  are  unsafe  for  any  but  the  highly-disciplined  scientific 
mind  to  attempt.  Nevertheless,  it  is  not  only  legitimate, 
but  imperative,  that  an  attempt  should  be  made  to  appreciate 
the  larger  significance  of  modern  discoveries — to  ascertain  to 
what  theory  of  the  Universe  these  discoveries  are  tending. 
Naturally,  our  conclusions  must  contain  a  large  amount  of 
speculation.  They  do  not  profess  to  state  the  actual 
structure  of  the  Universe  ;  they  profess  only  to  describe  that 

18 


THE  UNIVERSE  AS  A  WHOLE  19 

theory  of  the  Universe  which  modern  research  has  rendered 
more  probable  than  any  other  theory.  Within  large  limits, 
these  conclusions  are  certainly  correct ;  but  in  many  of  their 
details  modification  will  be  required  as  our  knowledge 
continues  to  advance. 

On  some  questions,  indeed,  it  seems  almost  inevitable  that 
we  must  for  ever  remain  in  ignorance.  How,  for  instance, 
can  it  ever  be  known  whether  there  exist  stars  right  away  to 
the  uttermost  limits  of  space  ?  We  cannot  even  ask  the  ques- 
tion intelligently ;  for  we  cannot  think  of  any  limits  to  space. 
We  cannot  imagine  to  ourselves  any  limit,  without  at  the 
same  time  being  always  able  to  think  of  regions  a  mile  or  a 
hundred  miles  beyond  that  limit,  even  though  measured 
through  absolute  void.  And  where  rational  questions  can- 
not be  framed,  there  can  be  no  hope  that  rational  answers 
will  ever  be  given.  We  quickly  reach  the  point  where  mere 
human  knowledge — and  the  possibility  of  human  knowledge 
— breaks  down  utterly  in  contact  with  the  infinite  and  the 
unknowable.  Our  science  is  like  a  small  candle  set  in  the 
midst  of  infinite  and  pitchy  darkness.  It  helps  not  at  all  in 
seeing  things  that  are  a  million  miles  away ;  and  even  if  we 
succeed  in  multiplying  its  light  a  million-fold,  we  shall  still 
be  no  wiser  as  to  space  a  trillion  miles  away,  and  we  shall 
have  approached  no  nearer  the  solution  of  infinite  distance 
or  the  boundaries  of  space. 

Nevertheless,  recent  study  goes  to  show  that  all  those 
stars  which  we  can  see  at  night,  and  all  those  others,  vastly 
more  numerous,  which  are  disclosed  by  powerful  telescopes, 
do  constitute  a  sort  of  single  island-universe,  in  the  midst 
of  infinite  space.  If  the  stars  were  scattered  continuously 
throughout  space,  we  should  expect  to  find  that,  as  each 
new  power  of  the  telescope  brought  into  view  a  fainter  class 
of  star,  this  fainter  class  would  be  more  numerous  in  a 
certain  proportion  than  the  brighter  stars  previously  known. 
They  are,  in  fact,  found  to  be  more  numerous,  but  not  in 
the  expected  proportion.  Observation  suggests  that,  at  a 


20    MODERN  SCIENCE  AND  MATERIALISM 

certain  remote  distance,  the  stars  become  rarer,  until  at 
length  a  region  is  attained  where  there  exist  no  stars  at  all. 

We  must,  then,  consider  our  Universe  as  an  isolated  system 
of  stars  and  nebulae;  and  the  question  arises  as  to  what 
shape  this  system  would  appear  to  be  if  we  were  able  to 
survey  it  from  an  external  position.  It  is  not  found  to  be 
a  sphere,  as  might  have  been  expected ;  it  is  an  oblate 
spheroid,  like  the  Earth  itself,  only  with  a  more  pronounced 
oblateness.  That  is  to  say,  our  Stellar  Universe  appears  to 
be  flattened,  say,  above  and  below :  the  stars  tend  to  be 
situated  in  a  single  flat  plane,  but  they  are  scattered 
sufficiently  on  each  side  of  this  plane  to  approach  a  spherical 
distribution. 

If,  once  again,  we  look  out  on  a  starlight  night,  we  see  a 
great  belt  of  luminous  material  stretching  right  across  the 
sky ;  this  belt  is  the  Milk.yL.-Way.  It  forms  a  complete  ring 
external  to  the  whole  Stellar  System,  and  more  remote  than 
the  stars  which  form  that  system.  We  must-  conceive  the 
Universe,  therefore,  as  a  flatteaed-out  sphere  surrounded  by  a 
ring,  the  ring  being  approximately  in  the  same  plane  as  that 
in  which  the  Stellar  System  is  flattened.  The  ring,  constitut- 
ing the  Milky  Way,  must  not  be  considered  as  quite  separate 
from  the  inner  system  of  stars  :  the  connection  between  them 
will  be  referred  to  later. 

It  is  now  necessary  to  obtain  some  idea  of  the.jiiagnitude 
of  our  Stellar  Universe.  The  distances  with  which  we  have  to 
deal  are  too  vast  to  be  conveniently  reckoned  in  miles.  We 
require  some  unit  of  measurement  far  larger  than  the  mile ; 
and  the  unit  most  convenient  for  our  present  purpose  will  be 
the  "light-year"" — that  is  to  say,  the  distance  travelled  by 
light  inTEe  "course  of  one  year.  This  unit  is  equal  to 
5,875,226,810,000  mites.  Light  travels  at  the  rate  of  rather 
more  than  186,000  miles  per  second.  The  distance  of  the 
Sun  may  be  estimated  from  the  fact  that  its  light  takes 
about  eight  minutes  to  reach  the  Earth.  But  distances  within 
the  Solar  System  fade  into  nothing  by  comparison  with  the 


THE  UNIVERSE  AS  A  WHOLE  21 

distances  of  the  stars.  The  nearest  of  the  fixed  stars  is 
a  Centauri,  a  bright  star  visible  only  in  the  Southern  Hemi- 
sphere. The  distance  of  this  star  is  such  that  its  light  takes 
four  years  and  three  months  to  reach  us. 

When  we  pass  from  the  nearer  parts  of  the  Universe  to  the 
more  rerri!5te7~fKe~  distances  with  which  we  have  to  deal 
transcend  all  power  of  the  imagination.  It  has  already  been 
stated  that  the  Milky  Way  forms  an  outer  ring  about  our 
star  system.  Various  estimates  have  been  made  as  to  its 
distance  ;  but  the  lowest  estimate  for  the  nearest  parts  of  the 
ring  place  it  at  a  distance  of  nearly  4000  light-years ;  that  is 
to  say,  the  light  travelling  from  it  to  the  Earth  at  the 
continuous  velocity  of  more  than  186,000  miles  per  second 
will  take  nearly  4000  years  to  arrive.  Other  estimates  are 
still  larger ;  one,  for  instance,  reckoning  the  time  at  over 
16,000  years  from  the  nearest  parts  of  the  Milky  Way. 

Now  it  follows  from*  these  figures  that  when  we  look  at  the 

Milky   Way,   we   see  it,   not  as  it  is  now,    but  as  it   was 

several    thousand   years   ago.     Conversely,   supposing    that 

there   exist   in   the   Milky   Way   other   suns    and    planets 

inhabited  by  people  like  our  own,  they,  looking  out  upon  the 

Earth,  would  see  it,  not  as  we  know  it,  but  as  it  was  perhaps 

when  palaeolithic  man  was  chipping  his  rude  flint  implements, 

or  sheltering  in  caves  from  the  rigours  of  the  Great  Ice  Age. 

It  must  not  be  supposed  that  there  is  anything  fanciful  or 

improbable  in  this  hypothesis.     Mankind,  as  a  rule,  are  so 

much  bound  down  by  the  narrow  conceptions  and  interests 

of  their  own  lives,  that  they  constantly  fail  to  realize  anything 

that  transcends  the  boundaries  of  their  personal  experience. 

The  hypothesis  that  life  exists  in  other  parts  of  the  Stellar 

Universe*ts~neither  fanciful  nor  improbable.    On  the  contrary, 

it  is  far  more  in  accordance  with  the  available  data  than  the 

opposite  hypothesis.     The  public  have  long  been  interested 

in  discussions  as  to  whether  there  is  life  in  the  planet  Mars, 

the  suggestion  being  based  upon  the  presence  of  supposed 

canals  on  the  surface  of  Mars,  which  have  some  appearance 


22    MODERN   SCIENCE  AND  MATERIALISM 

of  human  workmanship  and  design.     It  is  hard  to  say  in 
this  particular  case  that  these  canals  afford  evidence  of  any 
real  value  towards  the  presence  of  life.     All  forms  of  life 
with  which  we  are  acquainted  are  conditioned  by  a  certain 
kind  of  physical  environment :  life  can  only  exist,  for  instance, 
between  certain  limits  of  temperature,  and  only  where  there 
exist  sufficient  quantities  of  various  elements  (such  as  carbon, 
oxygen,  nitrogen,  hydrogen)  to  constitute  organic  matter. 
If  we  take  any  one  heavenly  body,  as,  for  instance,  Mars,  the 
chances  are  certainly  against  all  the  physical  conditions  of 
life  being  present.     But  if  we  estimate  the  chances  of  these 
conditions  being  realized  on  some  of  the  bodies  of  the-  Stellar 
Universe,  the  probability  becomes  so  high  as  to  amount  to 
a  practical  certainty.     Our  telescopes    disclose   to  us  very 
many  millions  of  stars  in  the  sky,   and  every  increase  of 
power  brings  into  view  further  millions.     And  these  are  only 
the  luminous  bodies.     There  can  be  no  doubt  whatever  that 
the  number  of  dark  bodies,  of  which  we  must  remain  ignorant, 
is  also  exceedingly  great,  very  possibly  much  greater  than 
that  of  the  luminous   bodies.     Is  it  to   be  supposed  that 
among  these  countless  millions,  one  only — the  one  we  know 
— supports   life  ?     Moreover,   every   star   and   every  planet 
passes   through   the   same  stages  of  evolution.     Beginning 
as  a  gaseous  body  of  vast  extent,  heat,  and  luminosity,  it 
gradually  contracts,  solidifies,  loses  its  luminosity  and  heat, 
until  it  becomes  dark  and  dead,  without  motion  of  any  sort 
upon  it,  and  fallen  to  the  temperature  of  space — the  absolute 
zero  of  cold.     The  Earth  has  reached  a  certain  stage  of  that 
evolution.     All  the  older  stars  and  their  planets  have  passed 
through  that  stage ;  all  the  younger  ones  are  approaching 
it.     Scattered  through  the  Universe  there  must  be  innumer- 
able bodies  which  are  approximately  at  the  same  stage  as 
the  Earth.     Moreover,  the  spectroscope  has  shown  that  the 
stars  are  composed  of  the  same  kinds  of  matter  as  our  Earth. 
In  many  bodies  of  the  Universe,  the  conditions,  therefore, 
cannot  be  very  different  from  those  in  which  we  ourselves 


THE   UNIVERSE  AS  A  WHOLE  23 

are  placed.  Are  we  to  say  that  on  our  Earth  alone  exists 
any  form  of  life  ?  We  know  that  similar  causes  of  necessity 
give  rise  to  similar  effects ;  and  if  we  find  life  on  the  one 
body  of  which  we  have  experience,  the  law  of  probability 
requires  us  to  believe  that  on  very  large  numbers  of  other 
bodies,  outside  the  range  of  our  observation,  life  must  also 
exist. 

But  not  necessarily  just  that  kind  of  life  which  we  know. 
Living  organisms  on  the  Earth  are  primarily  classified  into 
the  two  great  divisions  of  animal  and  plant.  But  we  have 
no  right  to  infer  that  there  can  be  no  other  kind  of  life 
than  what  can  be  brought  under  one  or  other  of  these  two 
divisions.  Where  the  physical  conditions  are  extremely 
similar  to  our  own,  we  may,  indeed,  expect  that  the  forms  of 
life  will  also  be  not  widely  different.  But  where  there  are 
considerable  dissimilarities,  we  should  not  be  surprised  to 
find  species  and  evolutionary  chains  which  could  not  be 
brought  within  the  limits  of  terrestrial  classification.  The 
dominant  forms  of  life  elsewhere  may  be  as  different  from 
animal  or  plant  as  these  two  are  different  from  one  another. 

Biologists  are  generally  agreed  that  life  is  a  product  of 
physical  and  chemical  conditions.  If  a  particular  set  of 
conditions  has  ^produced  life  upon  tEe  Earth,  then  the 
repetition  ot  that  set  of  conditions  in  some  other  part  of 
space  will,  with  the  same  inevitableness,  produce  life  there. 
If  the  set  of  conditions  is  identical  witlT  our  own,  then  also 
the  forms  of  life  will  be  identical.  It  is,  however,  exceedingly 
improbable  that  absolute  identity  can  anywhere  be  realized. 
The  mere  fact  that  there  cannot  be  identity  of  position — 
for  the  other  bodies  are  situated  in  other  parts  of  the 
Universe — introduces  at  once  a  difference.  The  forces  exerted 
upon  the  body  by  neighbouring  bodies,  and  by  the  centres 
of  gravity  of  the  Universe,  will  be  somewhat  different ;  and 
small  though  the  difference  may  be,  it  will  assuredly  suffice 
to  affect  profoundly  the  character  of  life  which  becomes 
established ;  for  we  know  how  delicatelyjpecies  are  adjusted 


24    MODERN  SCIENCE  AND  MATERIALISM 

to  their  environment,  and  how  any  change  of  the  environ- 
ment causes  (indirectly  rather  than  directly)  a  corresponding 
change  in  the  species  filling  that  environment.  Probably 
organic  evolution  on  the  Earth  has  been  controlled  by  an 
infinite  number  of  external-factors,  severally  quite  minute. 
A  difference  in  any  one  of  these  factors  would  have  affected 
profoundly  the  development  of  species.  Since  we  are  bound 
to  suppose  that  in  other  parts  of  the  Universe,  even  in  those 
parts  most  closely  resembling  our  own,  the  factors  which 
control  organic  evolution  will  differ  in  various  respects  from 
the  factors  to  which  we  on  the  Earth  are  and  have  been 
exposed,  we  are  equally  bound  to  infer  that  the  species  in 
those  other  parts  of  the  Universe  will  be  correspondingly 
different. 

When,  therefore,  we  inquire  what  are  the  probabilities  as 
to  any  one  species,  such  as  the  human  species,  existing  else- 
where, the  answer  becomes  much  more  speculative  and 
difficult.  It  all  depends  how  numerous  and  how  specialized 
are  the  factors  which  have  led  to  the  evolution  of  that 
species.  In  proportion  as  the  number  and  specialization  of 
those  factors  are  high,  the  probability  of  their  reproduction 
elsewhere  will  be  remote.  It  seems  probable  that  the  human 
species  has  arisen  in  response  to  a  vast  collocation  of  highly 
specialized  factors,  any  alteration  in  which  would  have  led 
to  corresponding  alterations  in  the  structure,  and  therefore 
in  the  functions,  of  the  species.  For  the  human  organism 
is  almost  infinitely  packed  with  detail.  There  are  various 
different  kinds  of  tissue,  and  a  great  congeries  of  diverse 
organs,  each  dependent  on  all  the  rest.  The  heterogeneity 
and  complexity  are  in  profound  contrast  to  the  homogeneity 
and  simplicity  of  the  most  elementary  forms  of  life.  It  seems 
probable,  therefore,  that  the  historical  factors  which  have 
brought  about  human  evolution  are  likewise  incredibly 
heterogeneous  and  complex,  and  are  correspondingly  unlikely 
to  have  occurred  in  the  same  collocation  in  other  parts  of  the 
Universe.  We  can  have  no  difficulty  in  perceiving  that  in 


THE  UNIVERSE  AS  A  WHOLE  25 

many  parts  of  the  Universe  there  must  have  arisen  the  little 
specks  of  undifferentiated  protoplasm  from  which  life  starts. 
Nor  can  we  have  any  difficulty  in  supposing  that  these  specks 
will  start  off  on  various  lines  of  evolution,  as  they  have  done 
on  the  Earth.  But  those  lines  of  evolution  will  be  controlled 
by,  the  local  conditions  ;  and  as  we  have  to  assume  some 
variety  in  local  conditions,  we  have  also  to  assume  variety 
in  the  species  which  are  ultimately  evolved.  In  comparing 
stellar  species  with  our  own,  we  should  expect  to  find  resem- 
blance on  broad  lines  only,  combined  with  multitudinous 
differences  of  detail. 

The next^  question     naturally     arising     concerns --  the 

probability  of  the  development  of  intellect  in  other- parts  of 
the  Stellar  Universe.  Is  there  likely  to  exist  anywhere  know- 
ledge, as  we  understand  the  word,  or  any  comprehension  of 
physical  truths,  or  any  power  of  consciously  altering  the 
environment,  such  as  we  possess  to  some  trivial  extent  ?  The 
answer  to  this  question  again  depends  on  the  further 
question  as  to  how  narrowly  specialized  are  the  factors  which 
favour  the  evolution  of  intellect ;  and  this  question  is  one 
which  biologists  cannot  answer.  We  may  well  believe,  indeed, 
that  the  factors  in  operation  are  far  more  numerous  and 
intricate  than  those  which  from  time  to  time  have  been 
suggested — such  as  the  opposability  of  the  thumb,  or  the 
power  of  speech.  But  we  may  also  note  that  intellect  of  a 
rudimentary  kind  is  characteristic  of  many  different  lines  of 
animal  evolution  on  the  Earth.  An  insect  or  crustacean  or 
fish  may  not  have  an  intellect  comparable  to  our  own ;  but 
they  certainly  have  the  rudiments  of  it.  The  raw  material 
of  intellect  is  distributed  widely  among  the  species  of  the 
Earth,  and  we  shall,  therefore,  perhaps  be  justified  in 
assuming  that  the  physical  factors  which  produce  this  raw 
material  are  not  very  precise  or  circumscribed.  It  would  not 
be  surprising  to  find  that  in  remote  globes  the  conditions  are 
sufficiently  similar  to  produce  something  analogous  to  what 
we  understand  as  intellect ;  and  if  the  raw  material  of 


26    MODERN  SCIENCE  AND  MATERIALISM 

intellect  is  scattered  at  large  throughout  the  Universe,  we  shall 
not  be  stretching  our  imagination  too  much  if  we  suspect 
that  here  and  there  it  maj^  have  blossomed  forth  as  it  has 
done  in  the  one~globe  of  which  we  have  experience.  Very 
probably,  indeed,  such  intellect  may  be  widely  different  from 
ours.  It  may  be  manifested  in  organisms  altogether  different 
from  ourselves.  It  need  not  necessarily  be  based,  like  ours, 
on  the  senses  of  sight,  touch,  and  hearing ;  but  upon  an 
altogether  different  set  of  senses,  of  which  we  have  no 
cognizance  or  conception.  And  yet  it  may  be  not  less 
powerful  than  ours :  it  may,  indeed,  be  far  more  powerful. 
In  some  of  the  myriad  stars  which  shine  upon  us  by  night, 
there  may  dwell  beings  who  even  at  this  moment  are  following 
the  doings  of  humanity  on  earth,  who  may  even  know  that 
at  this  moment  we  are  writing  about  them,  and  that  you  are 
reading  about  them. 

We  are  accustomed  to  regard  ourselves  as  lords  and 
masters  of  creation.  We  forget  that  we  live  upon  a  minor 
planet  revolving  around  a  minor  star.  -We  forget  the 
miserable  smallness  of  the  Earth,  which  passes  through 
all  its  transformations  from  luminous  gas  to  dead,  dark, 
solid  in  a  period  that  would  scarcely  be  more  than  a  day 
in  the  life  of  one  of  the  larger  stars.  If,  in  one  of  those 
stars,  evolution  gets  to  work  on  organic  matter,  the  time 
it  will  have  available  vastly  transcends  anything  we  know 
upon  the  Earth.  What  evolution  can  do  in  a  day  upon 
the  Earth,  may  it  not  do  far  more  completely  when  it  has 
a  million  years  to  work  in  ?  On  some  of  those  distant 
stars  there  may  well  be  intellect  comparable  to  our  own ; 
there  may  well  be  intellect  which  transcends  our  own  as 
greatly  as  ours  transcends  that  of  a  butterfly. 

With  this  possibility  in  mind,  let  us  turn  our  telescopes 
once  more  upon  the  heavens  to  see  whether  we  can  find 
any  traces  of  artificial  interference  with  the  regular  uni- 
formity of  Nature.  On  the  surface  of  one  of  the  nearest 
planets  there  are  markings  which  many  have  held  to  be 


THE  UNIVERSE  AS  A  WHOLE  27 

the  work  of  conscious  beings ;  but  the  evidence  on  which 
that  supposition  is  based  is  too  slight  to  throw  any  light 
upon  the  question,  or  to  strengthen  the  probabilities 
one  way  or  the  other.  In  no  other  part  of  the  Universe 
can  we  detect  the  smallest  deviation  from  the  blind  process 
of  natural  law.  The  various  stars  and  planets  swing  on 
their  courses  under  the  absolute  control  of  the  Laws  of 
Motion  and  Gravitation ;  in  the  myriads  of  stars  which 
shine  feebly  on  the  Earth,  not  one  furnishes  the  smallest 
indication  of  any  kind  of  living  process.  We  seem  to  be 
alone  in  the  midst  of  infinite,  silent,  and  lifeless  space. 

This  observation,  however,  carries  us  but  a  little  way. 
In  the  first  place,  no  artificial  construction  could  be  detected 
by  our  existing  methods,  unless  it  was  of  such  magnitude 
as  to  obliterate  the  light  or  alter  the  course  of  a  powerful 
sun  in  a  very  striking  and  conspicuous  degree.  The  highest 
flight  of  human  intellect  has  enabled  us  to  do  no  more  than 
effect  certain  insignificant  changes  on  very  limited  portions 
of  the  Earth's  surface.  Our  achievements  are  like  the 
scratchings  of  a  field-mouse  on  the  side  of  a  mountain. 
Such  scratchings  could  not  be  seen  except  by  the  closest 
observation,  and  for  an  observer  at  a  distance  they 
would  for  ever  be  hopelessly  outside  the  range  of  discovery. 
To  give  any  chance  of  discovery,  the  entire  mountain  must 
be  moved — and  must  be  moved  in  a  conspicuous  manner, 
plainly  not  in  accordance  with  natural  processes.  The  fact, 
therefore,  that  we  see  no  signs  of  interstellar  life  must  be 
taken  in  conjunction  with  the  fact  that  we  could  see  no 
such  signs,  unless  the  agency  which  wrought  them  were 
possessed  of  a  power  inconceivably  greater  than  our  own. 
We  find  no  signs  of  interstellar  intellect  on  a  large  scale ; 
but  that  fact  has  no  real  bearing  upon  the  problem  of  life. 
We  have  nothing  but  analogy  to  argue  from,  and  the 
utmost  that  analogy  can  lead  us  to  is  a  form  of  life  which 
may  modify  the  surfaces  of  stellar  bodies,  as  we  in  our  small 
way  modify  the  Earth's  surface.  Any  such  modifications — 


28    MODERN  SCIENCE  AND  MATERIALISM 

any  modifications  even  of  immeasurably  greater  extent — 
would  yet  remain  far  beyond  the  range  of  our  most  powerful 
scientific  instruments. 

Bereft  of  the  method  of  observation,  we  fall  back,  therefore, 
upon  that  of  analogy,  the  only  weapon  of  logic  with  which 
the  problem  can  be  touched.  And  recognizing  to  the  full 
the  shortcomings  of  that  weapon,  we  are  yet  bound  to  infer 
from  it  a  very  high  probability  that  life  is  scattered  in  various 
parts  of  the  Stellar  Universe  ;  and  a  considerable  probability 
of  intellectual  life,  very  likely  far  more  powerful  than  our  own. 

Let  us  suppose,  then,  that  such  life  exists  in  parts  of  our 
Stellar  System  distant  a  couple  of  thousand  light-years  from 
ourselves.  Let  us  suppose  that  intellectual  organisms  living 
there  are  in  so  far  similar  to  ourselves  as  to  be  susceptible 
to  the  sethereal  undulations  of  light.  What  would  such 
observers  see  if  they  are  now  directing  their  telescopes 
upon  the  Earth  ?  They  would  see  it,  not  as  it  is  now,  but 
as  it  was  when  Christ  was  alive.  If  their  instruments  are 
sufficiently  powerful,  they  may  at  this  moment  be  watching 
the  incidents  of  the  Crucifixion  and  the  burial  of  Christ. 
Or  they  may  observe  Caesar  conducting  the  Gallic  Wars ; 
and  in  England,  perhaps  the  Druids  worshipping  in  the 
temple  of  Stonehenge,  over  a  thousand  years  before  the 
Norman  Conquest.  To  them  our  present  doings  upon  the 
Earth  will  remain  unknown  for  another  two  thousand  years 
— veiled  in  the  impenetrable  darkness  of  the  future.  Their 
present  is  our  past ;  so,  too,  our  present  is  their  past.  The 
star  under  whose  shelter  they  live  may,  for  all  we  know,  have 
been  swept  away  by  a  cataclysm  in  the  age  of  Augustus. 
Yet  it  still  continues  to  twinkle  peaceably  upon  us  at  night ; 
its  past  alone  is  all  that  exists  for  us,  and  we  can  no  more 
say  what  has  happened  to  it  later  than  we  can  prophesy 
what  is  going  to  happen  to  ourselves.  Not  infrequently, 
indeed,  we  do  witness  in  the  heavens  a  sudden  new  star 
which  shines  with  great  brightness  for  a  time  and  then 
fades  away  again  from  view.  In  such  cases  we  know  that 


THE  UNIVERSE  AS  A  WHOLE  29 

we  are  witnessing  some  gigantic  collision  or  cataclysm  which 
occurred  in  the  depths  of  space  long  ages  ago.  We  must 
modify  our  conception  of  the  present.  As  we  include  within 
our  gaze  an  ever-widening  sphere  of  space,  we  are  at  the 
same  time  transferred^  ever  more  remotely  into  the  ages  of 
the  past.  Our  journeys  into  the  distant  regions  of  space 
are  at  the  same  time  journeys  backwards  along  the  stream 
of  time. 

Some  persons  have  even  suggested  a  still  more  daring 
speculation.  It  has  already  been  stated  that  light  travels  at 
the  rate  of  186,000  miles  a  second.  It  follows  that,  at  a  point 
distant  from  the  Earth  186,000  miles,  we  should  see  the 
Earth  as  it  was  a  second  before.  Plunging  still  further  into 
space,  we  should  reach  points  from  which  the  Earth  would 
appear  as  it  had  been  an  hour  previously,  a  day  previously, 
a  year  previously,  and  so  on  indefinitely.  Now  it  is  an  axiom 
of  science  that  no  motion  can  ever  be  lost ;  and  the  aethereal 
undulations  of  light,  if  not  absorbed,  must  continue  travelling 
for  ever  into  the  depths  of  space.  For  a  knowledge  of  the 
condition  of  the  Earth  at  any  special  past  period,  it  is  only 
necessary,  therefore,  to  take  up  our  position  at  a  distance 
from  the  Earth  where  the  light  emitted  during  that  period 
is  just  arriving.  The  whole  history  of  the  Earth  is  written 
in  expanding  spheres  of  light  stretching  away  to  infinite 
distance.  Every  event  that  has  occurred  upon  the  Earth  is 
now  working  its  effect  upon  the  aether  at  some  remote  region 
of  space ;  nor  is  it  possible  to  go  back  so  far  in  our  history 
that  we  cannot  indicate  a  part  of  space  where  that  history  is 
now  being  recorded  in  present  time,  and  would  leave  its 
impress  upon  any  photographic  plate  of  sufficient  delicacy  to 
receive  it.  It  has  been  suggested,  then,  that  the  history  of 
our  Earth  may  be  reflected  back  to  us,  possibly  by  intelligent 
beings  in  another  part  of  space,  possibly  by  a  device  of  our 
own  to  catch  it,  so  to  speak,  and  fetch  it  back.  If  this  wild 
speculation  could  ever  be  realized,  and  if  our  instruments 
could  be  refined  to  an  infinite  degree,  we  might  yet  be  able 


30    MODERN  SCIENCE  AND  MATERIALISM 

to  see  for  ourselves  and  to  photograph  for  ourselves  the 
actual  event  of  the  Crucifixion  of  Christ.  There  is  no  diffi- 
culty whatever  in  naming  the  portion  of  space  in  which  that 
Crucifixion  is  now  occurring  as  part  of  the  present,  to  any 
beings  who  may  live  there. 

Passing  now  from  the  problem  of  life,  let  us  revert  to 
thej£rAOj^_sJtmcture  of ^_our  Stella^  Universe.  As  already 
explained,  the  Universe  assumes  the  form  of  a  sphere,  some- 
what compressed  on  two  opposite  sides.  It  is  described  as 
being  of  the  shape  of  a  bun,  and  is  surrounded  by  the  ring  of 
the  Milky  Way  in  approximately  the  same  plane.  We  have 
attempted  to  give  some  idea  of  the  distances  of  the  various 
parts  of  the  system.  We  have  now  to  take  note  of  a  further 
fact,  namely,  that  the  stars  are  not  "fixed,1'  but  are  all  in 
motion,  though  their  inimehse  distance  renders  their  move- 
ment very  difficult  to  detect.  Their  motions  may  be  in  any 
direction,  though  certain  directions  are  more  favoured  than 
others.  Velocities  also  vary  within  wide  limits.  The  star 
which  moves  most  rapidly  of  any  yet  detected  is  known  as 
Lalande  1966,  which  is  travelling  through  space  at  the 
approximate  speed  of  200  miles  a  second.  Another  high- 
velocity  star  is  C.Z.  5*-  243,  which  is  moving  at  about  150 
miles  a  second.  It  may,  perhaps,  be  considered  fortunate 
that  it  is  moving  away  from  ourselves ;  and,  in  fact,  part  of 
its  apparent  motion  may  be  set  down  as  due  to  our  own 
motion  in  the  opposite  direction.  For  it  is  to  be  noticed 
that  there  does  not  anywhere  exist  in  Nature  an  absolute 
standard  of  rest  or  motion.  We  can  never  know  more  than 
the^relative  motions  of  bodies.  We_ can _  ascertain  that  two 
bodies  are  approaching  or  recedingjxam  one  another,  and  we 
can  ascertain.  J;he  amount  of  this  relative  motion ;  but  we 
cannot  say  whether  onfpFojKelr  or  both  are  moving,  unless 
there  is  some  outside  standard  of  comparison ;  and  when  we 
deal  with  the  Universe^. there  is  no  such  outside  standard. 
All  we  see  is  a  group  or  system  of  stars  changing  their 
positions  relatively JLO  one  another. 


THE  UNIVERSE  AS  A  WHOLE  31 

The  average  velocities  of  stars  are  very  much  lower  than 
those  above  named.  The  Solar  System  itself  moves  at  about 
thirteen  miles  a  second.  If  the  reader  has  followed  this 
chapter  at  all  carefully,  he  may  reflect  that  he  is  just  now 
more  than  5000  miles  away  from  that  part  of  space  in  which 
he  began  it,  and,  indeed,  that  he  has  travelled  forty  or  fifty 
miles  since  he  began  the  present  sentence.  It  is  curious  that 
the  planetary  nebulas  are  found  in  general  to  move  more 
rapidly  than  stars.  These  nebulas  consist  of  clouds  of 
luminous  or  dark  material  occupying  inconceivably  vast 
tracts  of  space.  It  is  useless  to  make  an  attempt  to  give  an 
idea  of  the  magnitude  of  such  nebulae :  the  area  covered  by 
the  whole  Solar  System  is  negligible  in  comparison.  These 
nebulas,  notwithstanding  their  tenuity  and  their  immense 
magnitude,  swing  along  through  space  at  an  average  rate 
of  more  than  fifteen  miles  a  second,  whereas  many  of  the 
brighter  stars  do  not  attain  a  quarter  of  that  speed.  The 
direction  of  motion  of  stars  is  not  altogether  haphazard.  In 
various  regions  of  the  sky  are  to  be  seen  clusters  of  stars 
which  appear  to  be  moving  together  with  the  same  velocity 
and  in  the  same  direction,  and  are  supposed  to  have  had 
a  common  origin.  Their  velocities,  indeed,  may  be  estimated 
to  differ  by  not  more  than  a  few  yards  a  second ;  for  any 
greater  difference  would  have  led  long  ago  to  the  dispersion 
of  the  group.  In  illustration  of  such  clusters  may  be  men- 
tioned the  Pleiades  and  also  the  Taurus  cluster,  both  visible 
on  winter  evenings  high  above  the  southern  horizon.  A 
better  known  but  more  widely  scattered  cluster  is  that  which 
includes  most  of  the  principal  stars  of  the  Great  Bear  ;  and 
with^them  is  supposed  to  be  associated  even  so  distant  a  star 
as  Sirius. 

In  addition  to  these  localized  star-clusters,  it  is  found  that 
the  movements^of  the^ars__as._a_whole  tendun__twQ-inain 
directions.  That  is  to  say,  although  there  are  stars  moving 
in  everj_direction,  and  others  which  scarcely  appear  to  be 
moving  at  all,  yet  there  is  evidence  of  some  influence  at  work 


32    MODERN  SCIENCE  AND  MATERIALISM 

which  tends  to  divide  the  Stellar  System  into  two  star-streams 
moving  in  opposite  directions  through  one  another  and 
independently  of  one  another.  The  explanation  of  this  fact 
will  be  considered  later. 

Wejiow  pass  on_to_cpnsider  the  methods  by_  which  the 
motions  and  distances i  of^ stars  are  discovered.  The  distance 
is  determined,  as  a  rale,  by  the  same  method  that  distances  of 
inaccessible  objects  on  the  Earth,  are  determined.  A  base- 
line is  carefully  measured,  and  then  the  exact  angular 
direction  of  the  distant  object  is  measured  from  the  two  ends 
of  the  base-line.  The  further  the  object  and  the  shorter  the 
base-line,  the  smaller  is  the  difference  of  direction  of  the 
object  as  viewed  from  the  two  ends  of  the  base-line.  Where, 
as  in  astronomical  investigations,  the  object  is  excessively 
remote,  the  angular  difference  of  direction  in  which  it  appears 
from  the  two  ends  of  the  base-line  is  excessively  small.  It  is 
necessary,  therefore,  to  make  our  base-line  as  long  as  possible. 
This  may  sometimes  be  done  by  taking  two  points  on  exactly 
opposite  parts  of  the  Earth's  surface.  The  distance  through 
the  centre  of  the  Earth  of  two  such  points  is  about  8000 
miles ;  and  this  may  be  used  as  a  base-line,  from  the  ends  of 
which  the  parallax,  or  difference  of  direction  in  the  apparent 
position  of  the  object,  may  be  attained.  In  practice,  however, 
such  a  base-line  is  far  too  short :  8000  miles  dwindles  to  a 
point  in  the  computation  of  astronomical  distances  ;  and  no 
results  can  be  obtained  from  it. 

The  base-line  commonly  used,  therefore,  is  the  diameter  of 
the  Earth^s  orbit.  The  apparent  direction  of  the  distant 
star  is  accurately  measured  ;  in  six  months'  time  it  is  then 
accurately  measured  once  again.  The  Earth  has  by  now 
swung  round  to  the  opposite  side  of  the  Sun,  and  the  object 
can  thus  be  viewed  from  two  comparatively  widely  separated 
points  in  space.  But  even  this  base-line  is  too  short  for 
measuring  the  distance  of  any  but  the  nearest  stars,  and 
calls  for  extreme  delicacy  and  refinement  of  the  measuring 
instruments.  The  only  available  method  of  obtaining  a  still 


THE  UNIVERSE  AS  A  WHOLE  33 

longer  base-line  is  to  wait  a  few  years  between  the  two 
observations.  In  the  course  of  that  time,  the  Earth  and  the 
whole  Solar  System  will  have  moved  a  great  distance  through 
space,  and  this  distance  may  be  employed  as  a  base-line; 
though  here  further  inaccuracies  are  introduced  owing  to 
ignorance  of  the  exact  length  of  this  base-line. 

The  motions  of  stars  are  in  part  determined  on  the  same 
principle.  The  motion  in  question  is  of  two  kinds :  firstly, 
that  across  the  line  of  sight,  called  proper  motion  ;  secondly, 
that  directly  towards  or  away  from  the  observer,  called  radial 
motion.  The  motion  of  every  star  is  made  up  of  these  two 
component  motions. 

The  calculation  of  proper  motion  is  simple  in  principle, 
though  singularly  difficult  in  practice.  Proper  motion  is 
seen,  of  course,  as  a  change  of  the  star's  position  in  the  sky. 
Owing  to  the  great  distances,  the  visible  changes  of  position 
are  very  minute.  Moreover,  accurate  observations  were  only 
taken  in  comparatively  recent  times.  If  we  had  records  of 
the  exact  positions  of  stars  two  or  three  thousand  years  ago, 
and  could  compare  them  with  their  positions  now,  we  should 
have  in  many  cases  a  good  idea  of  their  proper  motion ;  but 
in  fact  reliable  observations  do  not  extend  back  for  more 
than  about  150  years. 

The  radial  motion  presents  a  problem  that  at  first  sight 
appears  far  more  difficult,  but  which  in  fact  is  much  easier. 
Not  many  decades  ago,  the  problem  of  measuring  radial 
motion  appeared  to  be  not  only  insoluble,  but  necessarily 
and  for  ever  beyond  the  reach  of  human  intellect.  For  a 
star  is  nothing  more  than  a  point  of  light,  and  its  motion 
towards  or  away  from  the  observer  does  not  alter  its  appear- 
ance in  the  smallest  degree.  Unlike  a  planet,  it  has  no 
visible  disc.  If  we  turn  any  small  telescope  on  to  the 
planet  Jupiter,  we  recognize  at  once  a  visible  disc.  It  is 
more  than  a  mere  point  emitting  light.  But  when  we  come 
to  deal  with  a  star,  it  is,  and  always  remains,  a  point :  not 
the  most  powerful  telescope  in  the  world  can  make  it  more 
D 


34    MODERN  SCIENCE  AND  MATERIALISM 

than  a  mere  point  of  light.  How  then  can  its  motion  in  the 
line  of  sight  ever  be  detected  ? 

This  question  was  answered  by  the  spectroscope,  an  instru- 
ment by  which  we  can  learn,  not  only  the  radial  motion  of  a 
star,  but  also  the  chemical  substances  of  which  it  is  composed. 
When  a  star  is  moving  towards  us,  the  waves  of  light  which 
it  emits  are  compressed,  and  therefore  follow  upon  one 
another  with  unusual  rapidity.  When,  on  the  other  hand, 
it  is  receding,  the  aethereal  undulations  are  drawn  out  and 
follow  one  another  more  slowly.  The  spectroscope  can 
estimate  the  number  of  light  waves  arriving  in  a  given 
inter Vai",  "Ttnd  "hence  can  be  deduced  the  motion  of  the 
luminous  body  in  the  line  of  sight.  By  compounding  this 
motion  with  the  observed  proper  motion  of  the  star,  the 
actual  amount  and  direction  of  motion  are  obtained. 

A^few  words  must  be  said  concerning  the  origin  and 
development  of  the  Stellar  System.  The  common  hypothesis 
is  that  the  stars  have  developed  from  nebulae,  which  may  be 
described  as  masses  of  attenuated  cloud  of  incredible  dimen- 
sions drifting  through  space.  Such  a  nebula  is  to  be  seen  in 
the  well-known  constellation  of  Orion.  From  parts  of  this 
nebula  it  is  believed  that  new  stars  are  slowly  continuing  to 
be  formed,  and  the  nebula  itself  is  travelling  through  space 
with  the  same  velocity  as  neighbouring  stars  which  presum- 
ably have  been  formed  from  it.  It  is  still  a  subject  of 
controversy  as  to  what  is  actually  the  constitution  of  a 
nebula;  they  are  now  often  looked  upon  as  vast  col- 
lections of  meteoritic  fragments  constantly  colliding  with 
one  another.  But  stars  may  still  be  regarded  as  drops 
condensed  from  a  nebula-cloud.  During  the  first  stage  of 
condensation  they  increase  in  temperature  and  brightness ; 
then  gradually  the  radiation  into  space  of  heat  and  light 
begins  to  take  effect,  and  the  star  slowly  becomes  cold 
and  dark,  while  contracting  to  form  a  tightly- compressed 
solid  globe.  While  this  process  is  occurring,  the  star 
often  splits  up,  and  so  may  come  to  form  a  planetary 


THE  UNIVERSE  AS  A  WHOLE  35 

system  like  our  own.  Nearly  half  the  entire  number  of  stars 
are  "binaries."  That  is  to  say,  the  original  star  has  split 
into  two,  of  approximately  equal  size.  These  two  are  closely 
bound  together  by  the  mysterious  and  invisible  bond  of  gravi- 
tation. They  revolve  like  a  couple  of  dancers  round  their 
common  centre  of  gravity.  In  course  of  time,  as  age  over- 
takes them  and  they  become  cold  and  dark,  their  distance 
increases.  Various  forces,  notably  that  of  tides,  retard  their 
motion  ;  till  at  length  the  two  dead  spheres  swing  slowly 
round  one  another,  separated  by  great  distances. 

On  their  first  formation,  stars  as  a  rule  appear  to  have 
slow  motions  ;  but  as  they  decrease  in  brightness  and  in 
heat  they  gather  speed,  and  the  linear  motion  of  a  dead 
star  is  probably  much  higher  than  that  of  a  living  one. 
The  bright  stars  of  Orion  are  comparatively  young;  they 
move  also  at  slow  velocities,  which  will  in  the  course  of  ages 
probably  become  trebled.  Moreover,  the  origin  of  stars 
appears  to  take  place  chiefly  in  the  plane  of  the  Milky  Way. 
As  their  age  increases,  stars  tend  to  wander  from  this  plane, 
and  are  scattered  more  evenly  through  the  heavens. 

The  causes  of  stellar  motion  are  very  little  understood. 
The  distances  between  individual  stars  are  so  great  that 
mutual  gravitation  is  very  slight.  The  star  nearest  to  the 
Sun  is  a  Centauri ;  yet,  notwithstanding  its  proximity,  the 
attraction  of  the  Sun  acting  upon  it  for  a  year  does  not 
suffice  to  impress  upon  it  a  velocity  of  half  an  inch  per  hour. 
The  stars  thus  seem  to  move independently jof-  one  another, 
thou^h_they  are  subordinate  to  the  general  attraction  of  the 
whole  system.  Under  the  influence  of  this  general  attraction, 
they  appear  to  swing  backwards  and  forwards  like  a  pendulum 
from  one  border  to  the  other  of  the  sidereal  Universe.  On 
the  outskirts  of  the  Universe,  the  motion  of  the  star  would 
be  slow;  but  it  would  gather  force  as  it  approached  the 
centre.  If  the  stars  are  really  oscillating  to  and  fro  in  the 
Stellar  System,  it  is  conjectured  that  their  period  of  oscilla- 
tion would  be  of  the  order  of  300,000,000  years,  and  the 


36     MODERN  SCIENCE  AND  MATERIALISM 

general  age  of  our   Stellar  Universe  would  be   reckoned  in 
thousands  of  millions  of  years. 

We  are  still  no  nearer  an  answer  to  the  question  with 
which  we  opened  this  chapter :  Are  the  stars  scattered  about 
to  the  end  of  space,  or  are  they  clustered  into  a  single 
system  poised  in  the  midst  of  infinite  void  ?  We  have, 
indeed^sjgpn  reason  to  bgli^yje^Jbhat  the  visible  Universe  is 
bound  together  into  _a_single  system.  It  is  not  altogether 
easy  to  say  whether  certain  sidereal  objects  do  or  do  not  belong 
to  the  system.  Such  is  the  case,  for  instance,  with  the  Lesser 
Magellanic  Cloud,  whose  distance  is  so  incredibly  great  that 
its  light  takes  over  30,000  years  to  reach  the  Earth.  There 
are  yet  other  objects,  immeasurably  remote,  which  appear  to 
be  altogether  outside  our  Stellar  System.  These  objects  in 
particular  are  the  spiral  nebulae,  some  of  the  most  beautiful 
bodies  in  the  heavens.  They  consist  of  a  dense  core  or 
nucleus,  with  nebulous  matter  coiled  spirally  around  them. 
The  suggestion  has  been  made  that  these  spiral  nebulae  are 
nothing  else  than  other  stellar  universes  similar  to  that  which 
we  have  hitherto  described.  If  our  Stellar  System  is,  in 
reality,  a  spiral  nebula,  and  if  our  Sun  is  situated  near  the 
nucleus,  then  it  is  reckoned  that  the  nebulous  arms  coiled 
spirally  around  the  system  would  assume  very  much  the 
appearance  actually  observed  in  the  Milky  Way.  Moreover, 
the  two  principal  star-streams,  before  mentioned,  would 
represent  the  streaming  of  matter  to  or  from  the  nucleus 
into  the  nebulous  arms,  of  which  two  have  always  been 
I  observed. 

We  reach  the  conclusion,  therefore,  that  although  all  the 
visible  stars  are  united  to  form  a  single  universe,  there  very 
probably  exist  other  universes  divided  from  our  own  by  infinite 
tracts  of  void.  Our  imagination  will  not  allow  us  to  set  any 
limit  either  to  the  numbers  or  the  distances  of  such  other 
universes,  which  may  well  be  spread  in  endless  succession 
throughout  the  infinity  of  space.  Nor  have  we  the  slightest 
grounds  for  denying  the  probability  of  life  scattered  equally 


THE  UNIVERSE  AS  A  WHOLE  37 

far  beyond  the  confines  of  our  own  Universe.  The  more 
numerous  the  bodies  which  occupy  space,  the  more  unlikely 
does  it  become  that  we  alone  display  the  manifestations 
of  life.  Who  shall  say  that  we  are  not  even  now  under 
the  surveillance  of  intellectual  beings  in  another  globe  and 
another  universe  ?  All  we  know  is  that,  if  they  depend  upon 
light  for  their  information,  they  certainly  know  nothing  of  us 
as  we  are  now.  They  see  the  Earth,  perhaps,  long  before  the 
evolution  of  man :  in  their  telescopes  it  is  still  peopled  with 
Dinosaurs  and  strange  reptiles  which  for  untold  ages  have 
been  extinct.  It  is  possible,  however,  that  they  are  not 
dependent  upon  light ;  but  have  some  sense  that  it  is  based, 
for  instance,  on  gravitation.  Presumably,  gravitation  acts 
instantaneously  through  space — it  is  not  transmitted  like 
light — hence,  changes  in  the  distribution  of  matter  may  have 
instantaneous  effects  to  the  uttermost  limits  of  the  conception 
of  space. 

The  unity  of  our  own  Stellar  System  seems  to  be  indicated 
by  the  comparative  homogeneity  of  the  masses  and  motions 
observed.  The  masses  of  the  stars  do  not  vary  between  very 
wide  limits ;  their  motions  too  are  of  the  same  kind  of  order. 
In  a  universe  entirely  out  of  touch  or  any  relation  with  our 
own,  we  might  expect  to  find  at  least  an  infinite  variety  of 
motion.  Rest  and  motion  are  only  relative ;  and  if  another 
universe  has  never  had  the  smallest  connection  with  our  own, 
its  velocity  through  space,  relative  to  ourselves,  may  be  of  an 
order  utterly  beyond  the  range  of  our  imagination.  It  is, 
indeed,  more  likely  to  be  so  than  not.  But  supposing  the 
velocity  of  another  universe  were  so  far  commensurable  with 
our  own  as  to  resemble  that  of  light  by  comparison  with 
our  own ;  then  observers  situated  there  would,  if  their  world 
was  approaching  ours,  see1  the  events  of  centuries  crowded 
into  minutes,  just  as  the  cinematograph  displays  a  plant 
growing  to  maturity  in  a  few  seconds.  On  the  other  hand, 

1  Not,  of  course,,  by  direct  vision,  but  through  an  instrument  adapted 
for  the  detection  and  transformation  of  the  aethereal  waves. 


38    MODERN  SCIENCE  AND  MATERIALISM 

if  the  observer  was  receding  with  a  velocity  approaching  that 
of  light,  events  which  occupied  minutes  on  the  Earth  would 
be  protracted  to  centuries.  As  his  velocity  increased,  events 
on  the  Earth  would  appear  to  stand  still :  all  animation  would 
appear  to  have  been  suddenly  arrested  and  frozen  where  it 
was.  With  a  still  greater  velocity,  a  yet  more  curious  result 
would  be  witnessed.  Events  would  seem  to  move  backwards, 
and  the  history  of  the  Earth  would  be  gradually  retraced 
from  the  later  to  the  most  ancient  periods.  Moreover,  the 
Earth  would  not  be  seen  by  looking  towards  it,  but  by 
looking  in  exactly  the  opposite  direction  ;  for  the  observer 
would  be  catching  up  the  rays  of  light  emitted  from  the 
Earth,  and  he  would,  therefore,  only  come  in  direct  contact 
with  them  on  the  side  of  his  globe  most  remote  from  the 
Earth. 

Such  speculations  are  to  some  extent  invalidated  by  the 
so-called  Principle  of  Relativity.  According  to  this  doctrine, 
itself  of  highly  speculative  character,  all  objects  become 
flattened  in  the  direction  of  their  motion  through  space : 
motion  actually  changes  the  shape  of  the  moving  body.  As 
the  velocity  of  motion  approaches  that  of  light,  the  flattening 
tends  to  become  infinite,  until  at  the  actual  speed  of  light 
the  body  would  cease  to  have  any  thickness  at  all  in  the 
direction  of  its  motion.  It  would  then  exist  in  two  dimen- 
sions only,  instead  of  in  three.  From  this  it  is  inferred  that 
no  material  body  can  possibly  move  so  rapidly  as  light.  The 
Principle  of  Relativity  is  far  from  being  regarded  as  an 
established  fact ;  but  it  is  one  of  the  most  curious  hypotheses 
ever  framed  by  man. 

However  speculative  our  theories  may  be  as  to  the  general 
form  of  the  Stellar  Universe,  they  serve  at  least  to  bring 
home  one  point  of  fundamental  philosophic  importance — 
the  triviality  and  unimportance  of  Man  in  the  system  of 
Nature.  The  early  speculations  of  the  human  race  were 
founcled  on  the  assumption  that  Man  was  the  centre  of  all 
things,  the  purpose  for  which  all  things  existed.  Every 


V 


THE  UNIVERSE  AS  A  WHOLE  39 

individual  even  now  passes  through  this  age  of  speculation, 
equally  characteristic  of  the  childhood  of  the  individual  as  of 
the  race.  But  as  we  advance  in  knowledge  and  mental  power, 
we  tend  more  and  more  to  see  mankind  from  a  wider  point 
of  view — no  longer  the  centre  of  the  Universe,  but  an 
insignificant  item,  of  no  intrinsic  importance  whatever,  except 
to  themselves.  They  live  merely  upon  the  surface  of  a  planet 
revolving  round  the  Sun.  There  are  seven  other  such  planets 
of  considerable  size  revolving  round  the  same  Sun,  and  there 
are  nearly  a  thousand  known  minor  planets,  varying  in  size — 
the  largest  having  a  diameter  of  about  485  miles,  the  smallest 
of  fifteen  or  twenty  miles — mere  rocks  flying  through  space, 
the  smallest  objects  that  our  telescopes  can  see.  The  major 
planets,  again,  have  their  satellites ;  and  the  whole  solar 
system  thus  made  up  is  a  mere  unit  among  myriads  of  others 
in  the  Stellar  Universe.  That  Universe  itself  may  bejpnly 
another  single  unit,  among  a  multitude  of  other  universes ; 
and  if  at  this  point  we  cease  to  speculate,  it  is  not  because 
there  is  no  further  scope  for  speculation,  but  because  we  have 
already  far  outstripped  the  last  shred  of  solid  evidence  that 
our  instruments  can  provide  for  us.  Complete  and  absolute 
darkness  reigns  beyond.  If  we  learn  nothing  else  for  certain, 
we  learn  at  least  this :  that  the  farther  we  travel,  the  more 
obscure  and  insignificant  does  Man  appear.  And  three  points 
also  emerge,  which  we  shall  have  occasion  to  impress  later  on. 
Firstly,  the  uniformity  of  natural  "  law  "  remains  as  absolute 
in  these  regions  of  infinite  greatness  as  in  our  own  world  of 
human  dimensions.  Secondly,  no  sign  of  purpose  can  be 
detected  in  any  part  of  the  vast  Universe  disclosed  by  our 
.most  powerful  telescopes.  Thirdly,  this  great  new  sphere  of 
experience  affords  not  the  smallest  trace  of  evidence  for  the 
existence  of  any  spiritual  entity.  We  find  nothing  but  un- 
imaginable tracts  of  space  and  time,  in  which  move  bodies 
by  fixed  laws  towards  ends  which  are  wholly  fortuitous, 
and  have  not  the  smallest  relation  to  the  advantage  or 
requirements  of  Man. 


CHAPTER  II 

MATTER    AND    ENERGY 

WHEN  we  look  round  us  to  find  out  what  kind  of  objects 
or  phenomena  the  Universe  consists  of,  we  shall  at  first 
sight  notice  three  different  groups  in  which  all  the  facts 
of  our  experience  may  be  comprised.  In  the  first  place, 
there  is  what  we  know  as  matter,  existing  in  three  different 
forms,  of  solid,  liquid,  or  gas.  In  the  second  place,  there  are 
facts  of  a  different  character :  heat,  light,  sound,  electricity, 
motion,  which  appear  quite  different  from  what  we  know 
as  matter,  but  have  something  in  common  with  each  other 
which  causes  us  to  place  them  all  in  one  main  group  of 
external  phenomena.  In  the  third  place,  there  is  yet  another 
order  of  facts,  which  can  be  loosely  designated  under  the 
appellation  of  life  and  consciousness.  At  first  glance,  these 
vital  and  mental  phenomena  appear  to  have  nothing  in 
common  with  either  of  the  two  other  groups.  Their  pro- 
cesses take  place  within  us  and  are  subjective,  whereas  the 
processes  of  the  other  two  groups  are  outside  us,  and  there- 
fore objective.  In  these  three  fundamental  categories  all 
the  facts  of  human  experience  are  comprised. 

This  analysis  into  three  categories  is,  however,  merely 
provisional.  It  arises  from  our  first  casual  glance  to  see 
what  is  the  raw  material  out  of  which  the  Universe  is 
exclusively  built  up.  A  closer  examination  reveals  the  fact 
that  the  differences  between  the  groups  are  more  apparent 
than  real,  and  that  when  we  come  to  inquire  more  closely 
into  the  actual  constitution  of  each,  the  differences  sink 
away,  and  lead  us  to  believe  that  the  Universe  is  built 
up,  not  out  of  three  different  kinds  of  raw  material,  but 

40 


MATTER  AND   ENERGY  41 

from  one  kind  only,  which  manifests  itself  to  us  from  three 
separate  points  of  view.  The  third  group,  that  of  life 
and  consciousness,  is  dealt  with  in  the  following  chapter; 
the  present  chapter  is  devoted  to  a  closer  analysis  of  the 
first  two  groups. 

As  regards  matter,  the  fundamental  property  by  which  it 
is  distinguished  is  that  of  inertia.  That  is  to  say,  if  any 
portion  of  matter  is  at  rest,  it  cannot  start  into  motion 
without  the  action  upon  it  of  some  external  force ;  if  it  is 
already  in  motion,  it  equally  cannot  alter  its  velocity  or 
direction  of  motion  without  the  action  of  an  external  force. 
Resistance  to  change  in  its  state  of  rest  or  of  motion  is 
the  fundamental  property  of  matter. 

As  regards  the  second  group,  heat,  light,  electricity, 
etc.,  the  name  adopted  for  this  class  of  phenomenon  as  a 
whole  is  energy.  Just  as  matter  has  one  fundamental 
characteristic,  that  of  inertia,  so  energy  has  a  single  dis- 
tinguishing mark,  namely,  the  capacity  for  doing  "work." 
By  this  is  meant  that  it  can  give  rise  to  a  force  which  is 
capable  of  overcoming  the  inertia  of  matter,  and  thus 
causing  motion  in  a  portion  of  matter  previously  at  rest. 

The  first  great  Law  of  Physics  is  equally  applicable  to 
both  matter  and  energy.  It  states  that  matter  and  energy 
are  alike  indestructible  and  uncreatable,  and  that  such 
changes  as  we  observe  in  them  are  changes  only  of  form, 
during  which  in  either  case  the  absolute  quantity  is  totally 
unaffected.  We  burn  a  lump  of  coal,  and  matter  seems  to 
have  been  destroyed ;  but  if  we  collect  all  the  ashes  that 
remain  and  all  the  particles,  solid  or  gaseous,  that  have  been 
emitted  as  smoke  during  the  combustion — if  we  collect  all 
these  products  and  weigh  them  together,  we  find  their  total 
weight  to  be  identical  with  that  of  the  lump  before  it  was 
burnt.  So  also  in  the  sphere  of  energy.  If  we  drop  a  stone 
from  a  height  to  the  ground,  its  energy  of  motion  appears 
to  be  suddenly  destroyed.  But  measurement  has  shown  that 
at  the  precise  moment  when  the  motion  of  the  stone  is 


42    MODERN  SCIENCE  AND  MATERIALISM 

arrested,  there  come  into  existence  new  forms  of  energy, 
which,  on  being  added  together,  sum  up  to  the  exact  equiva- 
lent of  the  vanished  motion.  These  new  forms  of  energy 
are  of  various  kinds.  Much  of  it  will  appear  in  the  form 
of  heat  at  the  point  where  the  stone  strikes  the  ground. 
Some  will  appear  in  the  form  of  aerial  vibrations,  which 
we  know  as  sound.  There  may  also  be  an  emission  of  light ; 
there  may  be  electrical  or  magnetic  effects ;  and  there  will 
probably  be  a  sudden  appearance  of  small  quantities  of 
energy  in  various  other  different  forms.  When  all  these 
new  forms  of  energy  are  reduced  to  a  common  basis  and 
added  together,  their  sum  is  found  to  be  identically  equal 
with  the  lost  kinetic  energy,  due  to  the  motion  of  the 
stone. 

We  are  thus  led  to  the  conception  that,  whereas  matter 
may  exist  in  many  different  forms,  and  whereas  energy 
likewise  may  also  exist  in  different  forms,  yet  there  is  never 
within  human  experience  any  creation  or  destruction  of 
matter,  nor  is  there  any  creation  or  destruction  of  energy. 
When  matter  appears  to  be  destroyed,  'it  is  merely  passing 
from  a  more  visible  to  a  less  visible  form.  When  energy 
appears  to  be  destroyed,  it  has  merely  passed  into  other 
forms  less  immediately  obvious  to  our  senses. 

Hence  we  arrive  at  the  conclusion,  not  only  that  matter 
and  energy  are  the  raw  material  of  the  Universe,  but  that 
the  quantity  of  each  is  fixed  and  unalterable.  The  Universe 
consists  of  a  certain  definite  and  unchangeable  quantity  of 
matter  and  of  energy ;  all  that  happens  in  the  Universe 
consists  merely  of  some  alteration  in  the  form  of  the  matter 
or  energy.  From  the  widest  point  of  view,  the  Universe 
exhibits  a  vast  fund  of  matter  and  energy,  undergoing 
changes  of  form,  but  not  of  quantity.  Thus,  in  the  course 
of  time,  matter  passes  from  one  form  to  another,  energy 
passes  likewise  from  one  form  to  another.  The  fundamental 
fact  of  change — of  a  live  Universe  such  as  ours — is  a 
redistribution  of  matter  and  energy.  What  we  denominate 


MATTER  AND   ENERGY  43 

events  are  no  more  than  special  cases,  which  may  happen 
to  interest  us,  of  transformation  of  matter  and  energy.  All 
the  material  of  the  Universe  is  given  in  a  fixed  quantity 
of  matter  and  energy;  all  the  changes  or  events  occurring 
in  the  Universe  are  transformations  of  matter  and  energy 
from  one  form  to  another.  We  have  now  to  consider 
separately  these  two  groups  of  fundamental  phenomena, 
and  shall  first  turn  our  attention  to  the  constitution  of 
matter. 

In  the  preceding  chapter  we  dealt  with  magnitudes  so 
great  as  to  be  far  beyond  the  possibility  of  our  imagination. 
We  have  now  to  deal  with  magnitudes  so  small  as  to  be 
equally  beyond  the  range  of  possible  conception.  We  are 
to  pass  from  the  infinitely  great  to  the  infinitely  small,  and 
the  strain  upon  our  imaginative  faculties  will,  if  anything,  be 
increased  in  so  doing.  For  in  the  region  of  the  infinitely 
great,  we  deal  only  with  what  is  disclosed  to  us  by  the 
highest  powers  of  the  telescope.  But  in  the  region  of  the 
infinitely  small,  we  pass  far  beyond  the  highest  powers 
of  the  microscope.  We  are  not  to  any  great  extent  able 
to  infer  the  existence  of  bodies  beyond  telescopic  range; 
we  are,  on  the  other  hand,  able  to  infer  with  certainty  the 
existence  of  bodies  far  beneath  the  limit  of  visibility,  even 
with  the  most  powerful  microscope.  In  short,  no  microscope 
can  disclose  the  existence  of  even  the  largest  of  the  minute 
constituents  of  matter  which  we  are  about  to  describe. 

To  the  naked  eye  matter  appears  to  be  continuous,  more 
especially  when  it  is  in  the  solid  or  liquid  states.  This  ap- 
pearance, however,  is  due  solely  to  our  relatively  low  capacity 
of  vision.  In  reality,  matter  consists  of  innumerable  separate 
particles  of  incredible  minuteness,  and  possessing  rapid  motion 
of  several  different  kinds.  These  minute  particles  are  called 
molecules.  In  a  homogeneous  portion  of  matter,  all  the 
molecules  are  identical  in  size,  weight,  and  constitution.  In 
the  elementary  forms  of  matter,  their  diameter  is  less  than  a 
hundred-millionth  of  an  inch.  In  solids  they  are  regarded 


44    MODERN  SCIENCE  AND  MATERIALISM 

as  being  so  close  together  as  not  to  admit  of  movement 
among  one  another,  though  each  individual  molecule  has  a 
vibratory  motion  of  its  own.  In  liquids  they  are  still  close 
together,  but  not  so  close  as  to  prevent  motion  to  and  fro 
among  each  other.  In  a  liquid,  therefore,  in  addition  to  its 
vibratory  ,motion,  each  molecule  wanders  about  at  large  and 
is  not  confined  to  a  permanent  position.  In  gases,  a  far 
greater  amplitude  of  motion  is  possible,  and  the  distances 
between  the  molecules  are  considerable.  In  air,  for  instance, 
at  normal  temperature  and  barometric  pressure,  the  mole- 
cules are  all  travelling  on  the  average  at  about  a  thousand 
miles  an  hour — nearly  as  fast  as  a  rifle  bullet,  and  faster  than 
the  velocity  of  sound  through  air.  Their  motion  takes  place 
in  all  directions ;  and  since  they  are  incessantly  colliding 
with  one  another,  each  molecule  is  constantly  changing  the 
direction  of  its  motion.  On  the  average,  a  molecule  moves 
only  three-millionths  of  an  inch  before  colliding  with 
another;  and  since  their  velocity  is  so  great,  the  average 
number  of  collisions  for  each  molecule  is  about  six  thousand 
million  a  second.  The  total  number  of  molecules  in  a  cubic 
inch  of  air  is  about  440  trillion.1  One  further  dimension 
must  be  named  before  we  endeavour  to  realize  the  meaning 
of  these  unimaginably  small  dimensions — namely,  the  mass 
or  weight  of  the  molecules.  This,  of  course,  is  widely 
different  with  different  kinds  of  substance.  Normal  air  con- 
sists of  nitrogen  to  the  extent  of  more  than  three-quarters 
of  its  volume ;  and  the  weight  of  a  molecule  of  nitrogen  is 
of  the^  order  of  one  quadrillionth  part  of  an  ounce.  The 
weight  of  a  molecule  of  water  would  be  still  smaller. 

In  addition  to  their  motion  from  place  to  place,  the  mole- 
cules  in  many  cases  rotate  on  their  axes  at  inconceivable 
velocity.  A  few,  such,  for  instance,  as  the  molecules  of  argon 
(containing  only  one  atom),  are  believed  to  have  no  motion 

1  It  is  necessary  to  observe  that  I  use  the  words  "billion"  and 
<f  trillion  "  in  their  English,  and  not  their  American  sense.  By  billion, 
I  mean  a  million  million  ;  and  by  trillion,  I  mean  a  million  billion. 


MATTER  AND   ENERGY  45 

of  rotation ;  but  in  the  majority  this  motion  occurs.  The 
hydrogen  molecule,  for  instance,  rotates  qn  its  axis  about  five 
billion  times  a  second  ;  and  in  general  molecules  are  regarded 
as  rotating  not  less  than  a  million  times  in  the  thousandth 
part  of  a  second. 

These  figures  as  set  down  are  too  minute  to  convey  any 
sort  of  idea  to  the  imagination.  In" order  to  realize  them, 
however  imperfectly,  we  must  resort  to  an  analogy.  Sup- 
posing the  amount  of  water  that  can  be  contained  in  a  small 
thimble  were  magnified  to  the  size  of  the  entire  earth,  the 
molecules,  which  we  should  then  be  able  to  see,  would  appear 
about  the  size  of  footballs.  They  would  be  in  close  proximity 
to  each  other,  though  not  normally  in  actual  contact.  If  the 
thimble  had  originally  been  filled,  not  with  water,  but  with 
a  gas,  such  as  air,  and  this  quantity  of  gas  were  magnified  to 
the  size  of  the  earth,  the  football  molecules  would  then  appear 
to  be  some  ten  or  twelve  feet  apart  from  each  other.  Sup- 
posing their  kinetic  energy  were  magnified  in  the  same 
proportion  as  their  mass,  then  their  velocity  would  remain 
the  same,  and  they  would  all  be  in  motion  at  a  speed  too 
great  to  be  perceived  by  the  eye,  so  that  each  football  would 
present  a  mere  streak  as  it  travelled  on  its  way,  colliding 
several  times  a  second  with  other  footballs.  Moreover, 
each  football  would  be  spinning  on  its  own  axis,  in 
addition  to  its  motion  of  translation  from  one  point  to 
another.  If  we  assume  that  its  kinetic  energy  due  to  rota- 
tion is  increased  in  proportion  to  its  mass,  it  follows  that  its 
angular  velocity  would  be  diminished  in  inverse  proportion 
to  the  increase  of  radius ;  so  that  the  footballs  would  be 
rotating  on  their  axes  at  anything  from  once  or  twice  up  to 
several  thousand  times  a  second. 

However  difficult  and  imperfect  such  an  analogy  may  be, 
it  serves  at  least  to  indicate  that  matter  is  very  different 
from  what  a  casual  inspection  suggests.  It  is  not  continuous, 
as  appears,  but  consists  of  an  infinity  of  particles  of  incredible 
minuteness,  revolving  on  their  axes  at  inconceivable  velocity, 


46    MODERN  SCIENCE  AND  MATERIALISM 

and  dashing  to  and  fro  at  a  speed  which  the  imagination 
cannot  begin  to  realize.  Moreover,  as  will  shortly  appear, 
the  minute  impenetrable  particles  of  which  matter  consists 
fill  only  a  very  small  part  of  the  space  which  the  matter 
seems  to  occupy.  The  interstices  between  them  take  up 
far  more  room  than  the  particles  themselves.  For  the 
molecules  themselves  are  not  continuous  bodies  like  a  foot- 
ball, but  consist  mainly  of  "interstices,"  with  yet  smaller 
particles  wandering  about  in  them.  In  short,  it  is  believed 
that  the  volume  occupied  by  actual  material  particles  is  less 
than  one-millionth  of  the  total  space  apparently  occupied 
by  a  cold,  solid  body.  A  fragment  of  iron,  for  instance, 
consists  simply  of  empty  space  in  which  the  actual  particles 
are  flying  about  at  relatively  great  distances  from  each  other. 
This  consideration  introduces  us  to  our  next  step  in  the 
analysis  of  matter — the  question  as  to  what  is  inside  the 
molecules  themselves. 

Dalton's  atomic  theory,  after  being  entertained  as  a  pro- 
visional working  hypothesis  for  about  a  century,  has  at  length 
reached  the 'position  of  being  a  practical  certainty.  According 
to  this  theory,  the  molecules  consist,  as  a  rule,  of  several 
particles  still  more  minute  than  themselves,  these  smaller 
particles  being  called  atoms.  The  atoms  in  a  molecule 
preserve  a  certain  distance  from  each  other ;  but  they  are 
prevented  by  enormously  powerful  mutual  attraction  from 
exceeding  these  distances.  Some  molecules,  such  as  those 
of  argon,  sodium,  mercury,  and  zinc  in  gaseous  form,  consist 
only  of  one  atom,  and  the  atom  then  is  the  same  thing  as 
the  molecule.  Others,  such  as  oxygen,  hydrogen,  nitrogen, 
hydrochloric  acid,  common  table  salt,  etc.,  consist  of  two 
atoms.  The  molecules  of  carbon  dioxide  and  of  water  have 
three  atoms ;  that  of  ammonia  four  atoms ;  that  of  nitric 
acid  five  atoms ;  of  sulphuric  acid  seven  atoms,  and  so  on. 
Inorganic  substances  are  generally  characterized  by  few 
atoms  in  the  molecule ;  organic  substances  contain  many 
more.  Ordinary  sugar,  for  instance,  has  a  molecule  of  forty- 


MATTER  AND  ENERGY  47 

five  atoms,  alcohol  nine  atoms,  starch  some  multiple  of 
twenty-one  atoms,  morphine  forty  atoms,  while  a  dye 
such  as  helianthin  (whose  scientific  name,  by  the  way,  is 
dimethylamidoazobenzenesulphonic  acid)  consists  of  thirty- 
six  atoms  in  combination  with  a  subsidiary  molecule  of  water. 
Many  organic  molecules  consist  of  a  still  larger  number  of 
atoms,  and  many  are  too  large  to  admit  of  precise  chemical 
analysis.  Haemoglobin,  the  pigment  which  gives  blood  its 
red  colour,  consists,  according  to  one  reckoning,  in  the  case 
of  Man,  of  about  1900  atoms,  of  which  600  alone  are  carbon. 

Hitherto  we  have  paid  no  attention  to  the  fact  that 
molecules  are  of  as  many  different  kinds  as  there  are  different 
kinds  of  substances  in  existence.  The  difference  in  molecules 
of  different  substances  is  due  not  only  to  the  fact  that  they 
consist  of  different  numbers  of  atoms,  but  also  that  these 
atoms  are  of  different  kinds.  In  all,  there  are  believed  to 
exist  ninety-two  different  species  of  atoms.  Some  of  them 
are  very  rare  ;  some  have  scarcely  yet  been  discovered  at  all ; 
but  from  other  considerations,  it  is  known  that  the  total 
number  of  different  kinds  of  atom  in  existence  from  hydrogen 
to  uranium  must  be  ninety-two.1  Their  main  distinction  is 
in  their  weight ;  but  their  chemical  properties  also  are  widely 
different.  When  a  molecule  is  made  up  of  one  kind  of  atom 
only,  the  substance  is  called  an  element ;  where  it  includes 
atoms  of  different  kinds,  it  is  called  a  compound.  Thus 
hydrogen,  nitrogen,  and  oxygen  each  consist  of  two  similar 
atoms,  and  are,  therefore,  elements.  Ozone  consists  of  three 
atoms  (of  the  same  kind  that  make  up  oxygen).  Arsenic 
and  phosphorus  are  elements,  each  containing  four  similar 
atoms. 

Water,  on  the  other  hand,  consists  of  two  hydrogen  atoms 
and  one  oxygen  atom,  and  is,  therefore,  a  compound.  Table 
salt  consists  of  one  atom  of  sodium  and  one  atom  of  chlorine, 

1  These  ninety-two  kinds  represent  ninety-two  different  types  of 
atom,  rather  than  individual  homogeneous  things.  Jt  is  now  known 
that  each  type  may  include  several  different  varieties  or  ef  isotopes." 


48    MODERN  SCIENCE  AND  MATERIALISM 

and  is  a  compound.  Ammonia  is  a  compound  of  one  nitrogen 
with  three  hydrogen  atoms ;  sulphuric  acid  of  two  hydrogen, 
one  sulphur,  and  four  oxygen  atoms,  and  so  on.  Organic 
substances  are  invariably  compounds,  in  which  there  is  always 
at  least  one  carbon  atom  present.  All  forms  of  matter, 
therefore,  solid,  liquid,  and  gaseous,  are  built  up  out  of 
the  ninety-two  different  kinds  of  atoms.  Substances  are 
different  because  their  molecules  are  different ;  and  molecules 
are  different  because  they  contain  different  numbers  of 
atoms,  different  kinds  of  atoms,  and  because  the  atoms 
occupy  different  relative  positions  within  the  molecule. 

We  have  now  to  look  more  closely  at  the  atoms  them- 
selves, and  ascertain  some  idea  of  their  properties  and 
dimensions.  In  the  first  place,  it  is  clear  that  the  bond  of 
union  which  holds  them  together  in  the  molecule  must  be 
extraordinarily  powerful.  It  has  already  been  mentioned 
that  the  molecule  of  hydrogen  is  spinning  on  its  axis  at  the 
rate  of  five  billion  times  a  second.  This  involves  a  vast 
disruptive  tendency  on  the  atoms,  owing  to  the  centrifugal 
force  which  acts  powerfully  towards  driving  them  asunder. 
To  resist  this  centrifugal  force,  the  tenacity  of  the  bond 
between  them  must  be  at  least  a  thousand  times  greater 
than  that  of  steel ;  in  some  cases  the  stress  required  to 
separate  them  would  be  many  tons  to  the  square  inch. 
The  diameter  of  the  atom  is  of  the  same  order  as  that 
already  named  for  hydrogen  molecules.  A  molecule  con- 
sisting of  two  atoms  may  possibly  be  regarded  as  something 
like  a  dumb-bell,  except  that  in  the  case  of  atoms  the  con- 
necting link  is  not  material,  but  represented  by  their  vast 
cohesive  force.  An  important  difference  between  atoms,  as 
already  stated,  is  that  of  their  weight.  The  lightest  atom 
is  the  hydrogen  atom.  We  have  already  observed  that  the 
weight  of  the  nitrogen  molecule  is  of  the  order  of  one  quad- 
rillionth  of  an  ounce.  Since  there  are  two  atoms  in  the 
nitrogen  molecule,  the  weight  of  the  nitrogen  atom  would 
be  just  half  this  quantity.  The  weight  of  the  hydrogen 


MATTER  AND   ENERGY  49 

atom  is  about  one-fourteenth  of  that  of  the  nitrogen  atom. 
The  heaviest  known  atom  is  that  of  uranium,  which  weighs 
nearly  240  times  as  much  as  hydrogen.  Between  hydrogen 
and  uranium  are  ranged  all  the  rest  of  the  ninety-two  atoms, 
forming  a  scale  of  weights  that  increase  in  more  or  less 
regular  order.  Indeed,  it  was  long  ago  discovered  by  Men- 
delejeff  and  Meyer  independently  that  atoms,  or  rather 
elements,  exhibit  a  regular  sequence,  not  only  as  regards 
weight,  but  as  regards  chemical  properties.  At  that  time 
many  of  the  elements  were  still  undiscovered,  and  even  their 
existence  unsuspected ;  but  the  classification  of  Mendelejeff 
was  found  to  contain  a  number  of  gaps,  and  the  prophesy 
was  then  made  that  elements  would  some  day  be  found  to 
fill  those  gaps.  Thus  the  existence  of  the  metal  gallium 
was  prophesied  by  Mendelejeff  in  1871,  but  actually  discovered 
only  in  1875.  He  not  only  prophesied  correctly  its  atomic 
weight,  but  also  its  melting-point,  its  specific  gravity,  and 
many  of  its  chemical  properties.  The  existence  and  properties 
of  scandium  (discovered  in  1879)  and  of  germanium  (dis- 
covered in  1886)  were  similarly  predicted.  The  element 
helium  found  a  place  in  the  Periodic  Classification,  though 
it  had  not  at  that  time  been  discovered  on  the  Earth.  It 
had,  however,  strangely  enough,  been  discovered  in  the  Sun 
by  means  of  the  spectroscope,  and  its  discovery  on  our  own 
planet  was  not  effected  till  long  afterwards,  in  1895. 

Throughout  the  nineteenth  century  it  was  supposed  that 
atoms  were  the  smallest  particles  of  matter  that  existed,  and 
that  they  were  indivisible.  This  belief,  indeed,  was  usually 
incorporated  in  the  statement  of  the  atomic  theory.  It  was, 
however,  an  entirely  inessential  part  of  that  theory ;  no  con- 
clusions were  based  upon  it,  and  no  arguments  (other  than 
metaphysical)  were  drawn  from  it.  It  was  expressed,  not 
as  established  theory,  but  as  speculative  hypothesis  which 
future  learning  might  or  might  not  determine  to  be  correct. 
There  were,  in  fact,  many,  even  early  in  the  century,  who 
believed  that  the  various  types  of  atom  were  all  built  up 

E 


50    MODERN  SCIENCE  AND  MATERIALISM 

from  one  primordial  form  of  matter.  The  twentieth  century 
has  completely  vindicated  this  belief.  In  so  far  as  the  exist- 
ence of  molecules  and  atoms  is  concerned,  it  has  raised  the 
status  of  the  atomic  theory  from  that  of  a  mere  working 
hypothesis  to  that  of  an  established  doctrine.  On  the  other 
hand,  it  has  shown  with  equal  clearness  that  the  atoms  are 
not  indivisible,  nor  yet  the  ultimate  basis  of  matter.  Just 
as  molecules  are  made  up  of  a  varying  number  of  atoms,  so 
atoms  are  made  up  of  a  varying  number  of  yet  more  minute 
particles — particles  so  inconceivably  minute,  that  as  we 
examine  them  we  at  length  perceive  matter,  apparently  so 
solid  and  resisting,  actually  fade  away  altogether  and  vanish 
into  nothing.  We  pass  on,  therefore,  to  consider  the  internal 
structure  of  the  atom. 

The  old  conception  of  the  atom  as  a  hard  and  solid  frag- 
ment of  indivisible  matter  has  given  way  to  its  conception  as 
an  empty  sphere  of  space,  in  which  exist  a  varying  number 
of  particles,  whose  minuteness  is  such  as  to  preclude  any 
possibility  of  description.  These  particles  are  termed  electrons. 
^  Their  diameter  is  regarded  as  about  ^-.Voir  ^na^  °^  a  hydrogen 
atom.  That  is  to  say,  if  an  atom  were  magnified  to  appear 
of  the  size  of  a  large  room  in  an  ordinary  house,  the  electrons 
within  it,  on  the  same  scale,  would  be  only  just  visible  to  the 
naked  eye ;  and  if  one  of  them  were  lost,  it  would  be  almost 
hopeless  to  attempt  to  find  it  again.  Their  weight  is  likewise 
infinitesimal — according  to  the  most  recent  determinations 
it  is  T-gVzj-  °f  the  weight  of  the  hydrogen  atom.  The  com- 
parison of  the  electron  to  an  atom  of  oxygen  would  resemble 
the  comparison  between  an  ounce  and  a  ton.  Great  as  the 
contrast  in  weight  seems  to  be,  it  is  not  nearly  so  great  as 
the  contrast  in  volume. 

Electrons  are  found  to  be  precisely  identical,  from  whatever 
kind  of  matter  they  arise.  There  are  not  among  them  any 
varieties,  such  as  exist  among  the  atoms,  and  since  atoms  are 
built  up  out  of  electrons,  it  is  clear  that  the  varieties  of  atoms 
must  be  due  to  a  difference  in  the  number  of  electrons  which 


MATTER  AND  ENERGY  51 

they  contain.  Now  as  we  pass  along  the  series  of  the  ninety- 
two  different  varieties  of  atoms,  in  the  order  of  their  increas- 
ing weight,  it  is  believed  that  each  atom  contains  one  more 
electron  than  the  atom  which  immediately  precedes  it.  Thus 
hydrogen,  the  lightest  of  the  elements,  would  have  an  atom 
containing  one  electron.  Uranium,  the  heaviest,  would  have 
an  atom  containing  ninety-two  electrons.  Nitrogen,  being 
seventh  on  the  list  in  the  order  of  ascending  atomic  weights, 
would  have  seven  electrons  to  the  atom,  and  oxygen,  which 
fills  the  next  place,  would  have  eight.  In  all  these  cases, 
the  complexity  of  the  atom  may  be  increased  by  a  number 
of  additional  electrons  contained  within  the  nucleus.  Thus 
all  the  elements  from  which  all  forms  of  matter  are  com- 
pounded are  built  up  from  one  single  kind  of  unit,  aggregated 
into  atoms  of  greater  or  lesser  number  of  those  units. 

The  most  important  property  of  the  electron,  however, 
still  has  to  be  named.  It  carries  an  enormously  powerful 
charge  of  negative  electricity.  The  various  particles  of 
matter,  hitherto  mentioned,  have  been  electrically  neutral ; 
but  the  electron,  by  far  the  smallest  of  them  all,  carries  an 
electric  charge  greater  than  any  other  known  within  the 
limits  of  human  experience.  If  it  were  possible  that  small 
particles  of  matter,  just  visible,  should  carry  corresponding 
charges,  and  if  two  such  small  particles  could  be  placed  in 
contiguity,  the  force  of  repulsion  between  them  would  amount 
to  countless  millions  of  tons. 

The  electrons,  nevertheless,  are  held  together  somehow 
within  the  atom.  It  is,  therefore,  assumed  that  there  exists  in 
the  atom  a  central  nucleus,  consisting  of  a  positive  electrical 
charge,  of  an  amount  that  is  equal  to  the  sum  of  the  charges 
on  the  electrons.  For  reasons  about  to  be  mentioned  the 
diameter  of  this  central  nucleus  must  be  far  less  even  than 
the  diameter  of  an  electron.  It  is  by  far  the  smallest  measure- 
ment known  to  science;  so  small,  indeed,  that  for  many 
purposes  it  may  be  regarded  as  a  mere  geometrical  point. 
It  is  probable  that  the  electrons  revolve  in  circular  orbits 


52    MODERN  SCIENCE  AND  MATERIALISM 

round  the  central  nucleus  and  that  the  atom  thus  resembles 
a  miniature  solar  system,  with  planets  revolving  round  a 
central  sphere  of  attraction.  If  this  be  the  case,  then  it  turns 
out  that  the  infinitely  small  and  the  infinitely  great  are 
arranged  upon  a  common  plan.  Summing  up  the  conception 
of  matter  thus  far  attained,  we  find  it  to  consist,  in  a  final 
analysis,  of  a  planetary  system  of  electrons  and  nucleus.  The 
differences  in  the  number  of  electrons  (and  hence  of  the  charge 
on  the  nucleus)  give  rise  to  ninety-two  different  kinds  ot 
atoms.  These  atoms,  compounded  with  each  other  in  number- 
less different  ways,  produce  the  molecules  from  which  all  the 
different  kinds  of  matter  are  built  up. 

At  length,  therefore,  we  are  in  a  position  to  approach  the 
problem,  what  is  matter  ?  It  resolves  itself  into  the  problem, 
what  are  electrons,  and  what  is  the  central  nucleus?  We 
defined  matter  at  the  outset  as  that  which  possesses  inertia, 
that  is  to  say,  a  resistance  to  any  change  in  its  state  of  rest 
or  motion.  Nearly  forty  years  ago  it  was  pointed  out  by 
Sir  J.  J.  Thomson  that  a  sphere  charged  with  electricity 
must  possess  a  somewhat  greater  inertia  than  an  equal  sphere 
not  so  charged.  For  all  ordinary  magnitudes,  the  difference 
is  so  slight  as  to  be  incapable  of  detection  by  the  most 
sensitive  instrument ;  but  the  very  remarkable  principle  was 
established  that  inertia  might  be  due,  not  only  to  mass,  but 
also  to  electrical  charge.  It  is  suggested  that  a  body  is 
actually  heavier  when  charged  with  electricity  than  when 
electrically  neutral.  When  the  body  is  moving  at  low  velo- 
cities, the  electrical  inertia  is  very  slight,  but  it  increases 
with  the  velocity  of  the  body,  until  at  velocities  approaching 
that  of  light  it  becomes  a  very  considerable  factor  in  the  total 
inertia  of  the  body. 

With  bodies  of  ordinary  magnitude,  there  can  be  no 
approach  to  any  such  velocity  as  that  of  light.  But  an 
electron  is  not  a  body  of  ordinary  magnitude.  Not  only  is  it 
inconceivably  small,  but  it  carries  an  inconceivably  immense 
charge  of  electricity,  and  it  is  often  found  to  travel  at  an 


MATTER  AND   ENERGY  53 

inconceivably  high  velocity.  The  main  peculiarity  of  radium, 
and  other  radio-active  elements,  is  that  their  atoms  are  dis- 
integrating, and  the  electrons  shot  forth  into  the  surrounding 
space.  The  velocity  at  which  they  are  driven  out  is  often 
higher  than  150,000  miles  a  second.  Whether  as  regards 
size,  or  as  regards  electrical  charge,  or  as  regards  velocity,  the 
electron  is  fundamentally  different  from  any  of  the  magnitudes 
ordinarily  dealt  with.  The  interesting  question  arises,  there- 
fore, as  to  how  far  the  inertia  of  an  electron  is  due  to  its 
mass,  and  how  far  to  its  electrical  charge.  The  problem  has 
been  solved :  the  whole  of  its  inertia  is  due  to  its  charge ; 
there  is  none  left  over  that  can  be  attributed  to  its  mass. 
But  since  inertia  is  the  one  distinguishing  character  of  mass — 
that  is,  of  matter — the  discovery  is  tantamount  to  the  state- 
ment that  an  electron  has  no  mass — that  it  is  not  matter  at 
all,  but  simply  a  charge  of  electricity  suspended  without 
bodily  support,  though  having  a  definite,  if  exceedingly 
minute,  diameter  and  volume. 

As  regards  the  positively  charged  nucleus  of  the  atom,  the 
same  astonishing  fact  has  not  yet  been  substantiated  by  any 
definite  proof.  It  appears  highly  probable,  however,  that  the 
nucleus  is  also  a  disembodied  electrical  charge.  If  that  is 
the  case,  its  diameter  must  be  a  small  fraction  of  the  diameter 
of  the  electron.  The  mass  of  the  atom  is  certainly  due 
almost  wholly  to  the  nucleus,  whose  weight,  therefore,  must  be 
nearly  two  thousand  times  that  of  an  electron.  The  charge 
carried  by  the  nucleus  is  necessarily  equal  to  that  carried  by 
the  attached  electrons.  The  electrons  in  an  atom  are  far  too 
few  to  account  for  its  known  weight ;  and  if  that  weight  is 
entirely  due  to  electrical  charge  on  the  nucleus,  such  charge 
must  attain  a  far  higher  degree  of  concentration  even  than 
the  charge  on  an  electron.  This  supposition  requires  us  to 
regard  the  actual  volume  of  the  nucleus  as  proportionally 
smaller  than  the  volume  of  the  electron.  Charges  being  the 
same,  the  necessary  concentration  on  the  nucleus  can  only  be 
achieved  by  reduction  of  its  diameter. 


54    MODERN  SCIENCE  AND  MATERIALISM 

Let  us  now,  at  the  conclusion  of  this  analysis,  revert  to  our 
former  analogy,  to  see  what  matter  would  look  like  if 
magnified  to,  say,  a  thousand  million  diameters,  so  that  the 
contents  of  a  small  thimble  appeared  to  become  the  size  of 
the  earth.  Even  under  this  great  magnification,  the 
individual  electrons  would  still  be  too  small  to  be  seen  by  the 
naked  eye.  Small  aggregations  of  these  invisible  electrons, 
moving  in  invisible  orbits  round  a  centre,  would  be 
aggregated  to  form  atoms,  and  these  again  to  form  molecules, 
appearing  (if  they  could  be  seen)  to  occupy  about  the  same 
volume  as  a  football.  The  first  circumstance  that  strikes  us 
is  that  nearly  the  whole  structure  of  matter  consists  of  the 
empty  spaces  between  electrons.  Matter,  which  appears  to 
us  so  continuous  in  its  structure,  is  really  no  more  than  empty 
space,  in  which  at  rare  intervals  here  and  there  an  inconceiv- 
ably minute  electron  is  travelling  at  high  velocity  upon  its 
way.  It  ceases,  therefore,  to  be  remarkable  that  X-rays  can 
penetrate  matter  and  come  out  on  the  other  side.  How 
should  the  tiny  electrons  obstruct  their  passage  ?  It  ceases 
to  be  remarkable  that  an  electron  from  radium  can  be  shot 
clean  through  a  plate  of  aluminium  ;  for,  from  the  electron's 
point  of  view,  the  aluminium  plate  is  very  little  different 
from  empty  space.  And  if  a  thimbleful  of  solid  substance 
were  magnified  to  the  dimensions  of  the  earth,  the  curious 
circumstance  is  that  we  should  actually  see  nothing  at  all. 
The  electrons  would  still  be  too  small ;  we  should  see  only 
the  interspaces,  which  are  relatively  so  great  as  to  occupy 
apparently  the  entire  field  of  view.  Clearly,  matter  is  very 
different  from  what  it  appears  at  first  sight  to  the  unaided 
vision  and  the  uneducated  mind. 

The  doctrine  that  matter  ultimately  consists  of  disem- 
bodied electrical  charges  appears  to  many  people  so  inconceiv- 
able, and  so  far  removed  from  common  sense,  as  to  be 
altogether  incredible.  We  appear  to  have  passed  beyond  the 
region  of  physics  into  that  of  metaphysics,  where  paradox 
and  magic  take  the  place  of  solid  fact.  Nevertheless,  we  are 


MATTER  AND  ENERGY  55 

bound  to  follow  out  the  results  of  physical  experiment  and 
deduction,  to  whatever  incomprehensible  conclusion  they  may 
lead  us.  We  must  not  be  trammelled  by  the  narrow  limita- 
tions of  "  common-sense,"  which,  after  all,  has  only  developed 
within  us  through  contact  with  the  world  we  know,  and  may 
be  utterly  misleading  if  carried  with  us  into  the  utterly  new 
world  which  we  are  trying  to  explore — the  world  of  the 
infinitely  small.  On  such  a  voyage  of  discovery  we  must 
shed  our  prejudices  at  the  start ;  they  belong  only  to  the 
common  world  we  know ;  we  must  leave  them  behind,  and 
follow  the  guiding  light  of  physics  into  whatever  astounding 
mysteries  it  may  lead  us.  When  at  last  we  find  ourselves 
standing  in  the  midst  of  a  stranger  land  than  our  imagi- 
nations ever  dreamt  of,  it  is  wiser  to  condemn  the  former 
limits  of  our  imagination,  than  to  question  whether  this  land 
really  does  exist.  It  certainly  does ;  that  at  least  is  by  far 
the  most  probable  verdict  of  physics.  If  it  is  difficult  to 
realize,  the  error  is  more  likely  to  be  due  to  the  feebleness  of 
our  imaginative  faculties  than  to  any  doubt  as  to  the  real 
facts. 

But  are  the  facts,  after  all,  not  capable  of  being  brought 
within  our  imagination,  after  it  has  been  stretched  somewhat 
and  freed  from  the  rigidity  of  convention  and  habit  ?  The 
main  obstacle  to  be  overcome  is  the  resolution  of  matter  into 
disembodied  electrical  charges.  All  our  former  experience 
of  electricity  teaches  us  to  regard  it  as  a  particular  state 
of  matter.  We  find  it  hard  to  conceive  a  charge  of  elec- 
tricity apart  from  a  portion  of  matter,  on  which  the 
charge  resides.  It  seems  much  like  speaking  of  an  actual 
motion  without  any  moving  body.  Yet  there  are  pheno- 
mena within  our  ordinary  experience  which  present  a 
tolerably  complete  analogy.  Electricity  is  one  form  of 
energy ;  and  we  are  familiar  with  other  forms  of  energy 
which  have  no  material  substratum.  Such  a  form  of  energy 
is  light,  which  traverses  empty  space,  and  works  its  effect 
on  our  sense-organs  without  any  basis  of  matter  whatever. 


56    MODERN  SCIENCE  AND  MATERIALISM 

It  is  a  form  of  energy  which,  like  the  electron,  occupies 
space  while  yet  wholly  immaterial.  As  to  whether  light  has 
inertia — whether  it  has  an  actual  weight,  like  the  electron — 
is  riot  yet  determined.  The  question  is  likely  to  be 
determined  by  the  observations  taken  during,  the  recent 
solar  eclipse;  but  the  result  is  not  known  at  the  time  of 
writing. 

So,  also,  radiant  heat  has  no  material  basis.  Light  and 
heat  are  transmitted  to  us  from  the  sun,  and  travel  across 
space  at  a  velocity  that  would  be  impossible  if  they  were 
tied  up  to  even  the  smallest  particles  of  matter.  True, 
the  current  theory  of  radiant  heat  and  light  is  that  they 
are  undulations ;  and  since  it  is  hard  to  imagine  undulations 
without  anything  to  undulate,  the  universe  is  regarded  as 
being  filled  by  an  all-pervasive  aether,  700,000  times  more 
elastic  than  air.  But  this  aether,  whatever  else  it  may  be, 
is  not  matter.  The  properties  which  it  must  possess  if 
it  is  to  account  for  the  facts  for  which  it  was  invoked, 
could  not  possibly  exist  together  in  matter.  It  must  have 
a  rigidity  greater  than  that  of  steel ;  it  must  have  a 
density  many  million  times  greater  than  that  of  lead,  and 
yet  it  must  be  so  attenuated  that  the  stars  and  planets 
can  fly  through  it  at  huge  velocities  without  the  smallest 
sign  of  retardation  or  friction.  Such  a  collocation  of 
properties  is  certainly  not  compatible  with  our  conception 
of  matter.  Thus  radiant  energy  exists  apart  from  any  basis 
that  we  should  recognize  as  matter;  and  if  radiant  energy 
undoubtedly  so  exists,  why  should  not  electrical  energy  also 
in  the  form  of  an  electron  ? 

Psychologically  also,  there  is  little  reason  for  astonish- 
ment. Matter,  as  will  be  hereafter  explained,  is  not  an 
immediate  datum  of  consciousness,  but  an  inference.  All 
we  have  immediate  knowledge  of,  without  inference,  is  our 
sense-impressions.  All  knowledge,  save  that  of  direct 
sense-impression,  is  derived  by  the  methods  of  generalization 


MATTER  AND  ENERGY  57 

and  deduction.  We  know  that  in  the  case  of  light  and 
heat  sense-impression  may  be  produced  by  energy  alone 
apart  from  matter.  If  some  sense-impressions  are  so  pro- 
duced, no  difficulty  remains  in  supposing  that  they  may 
all  arise  iri^  the  same  way.  II  riy  a  que  le  premier 
pas  qui  coute.  Every  physicist  admits  that  some  inertia 
is  of  electrical  origin.  But  in  doing  so,  the  principle  of 
immaterial  inertia  is  conceded.  Logically  there  can  be 
no  objection  to  supposing  that  the  whole  of  inertia  may 
be  due  to  the  same  origin.  The  ordinary  induction  ot 
electric  currents  may  make  the  difficulty  seem  less. 

The  tendency  of  recent  physical  science,  then,  is  to 
obliterate  the  distinction  between  matter  and  energy.  The 
Universe  no  longer  seems  to  be  occupied  by  two  fundament- 
ally different  forms  of  existence.  It  is  simply  the  seat  of 
.electrons,  which  give  rise  to  what  we  know  as  matter  and 
energy,  manifesting  themselves  in  a  great  variety  of  different 
forms.  True,  we  still  have  a  dualism  at  the  root  of  all 
phenomena.  If  it  is  no  longer  the  dualism  of  matter  and 
energy,  it  is  that  of  positive  and  negative  electricity.  But 
the  contrast  between  these  two  is  far  more  easily  bridged 
by  the  mind  than  the  contrast  between  matter  and  energy. 
They  are  the  same  kind  of  existence ;  the  same  laws  apply 
equally  to  both  ;  their  effects  upon  the  neutral  environment 
are  in  all  cases  identical.  We  have  approached,  by  this 
doctrine,  far  nearer  to  the  complete  unification  of  knowledge, 
which  has  long  been  the  goal  of  philosophy. 

We  pass  now  from  the  consideration  of  matter  to  that 
of  energy,  in  its  normal  and  recognized  form.  The  most 
fundamental  law  of  energy,  as  already  stated,  is  that  of 
its  permanence.  Like  matter,  it  is  capable  neither  of  being 
destroyed  nor  created,  but  only  of  changing  its  form.  Light 
can  change  into  heat,  heat  into  electricity,  electricity  into 
motion,  and  so  on ;  but  the  sum-total  of  the  energy  remains 
unaltered.  For  every  disappearance  of  energy  in  one  form, 


58    MODERN  SCIENCE  AND  MATERIALISM 

there  is  a  fresh  and  equivalent  appearance  of  energy  in  some 
other  form.  All  these  forms  of  energy  can  ultimately  be 
resolved  into  some  kind  of  motion.  Heat,  for  instance, 
is  molecular  motion.  The  difference  between  a  hot  body 
and  a  cold  body  is  merely  this,  that  in  the  hot  body  the 
molecules  are  vibrating  more  rapidly  than  in  the  cold  body. 
So  that  if  kinetic  energy — i.  e.  the  energy  possessed  by  a 
body  in  virtue  of  its  motion — is  transformed  into  heat,  what 
really  happens  is  that  the  motion  of  the  body  as  a  whole 
is  converted  into  motion  of  its  individual  molecules.  In 
the  same  way,  the  electric  current  is  the  motion  of  electrons. 
The  current  consists  of  a  stream  of  myriads  of  electrons 
flowing  at  huge  velocities.  In  an  ordinary  sixteen-candle- 
power  electric  lamp,  the  number  of  electrons  passing  through 
the  filament  each  second  is  so  great  that,  if  the  entire  popula- 
tion of  London  were  told  off  to  count  them,  and  if  they 
counted  at  the  rate  of  two  a  second,  without  ever  stopping 
day  or  night,  it  would  take  them  ten  thousand  years  to 
complete  the  task. 

Sound  also  is  motion — a  vibrating  motion  of  the  mole- 
cules of  air  or  other  substance  through  which  the  sound 
is  conducted.  Light  is  regarded  as  a  vibratory  motion  of 
the  same  character,  conducted  by  the  aether.  In  short, 
all  forms  of  energy  may  be  regarded  as  motion ;  and  all 
the  phenomena  of  physics  can  be  represented  in  terms  ot 
matter  arid  motion.  One  proviso  indeed  has  to  be  made. 
All  the  above-named  forms  of  energy  are  kinetic — they  imply 
something  or  other  that  is  moving;  but  there  is  another 
species  of  energy,  named  potential  energy,  in  which  nothing 
is  moving,  nothing  happening  at  all.  If  a  stone  is  thrown 
up  into  the  air,  and  falls  upon  the  ground  again  at  the 
same  level  from  which  it  was  thrown,  the  sudden  destruction 
of  its  motion  on  reaching  the  Earth  gives  rise,  as  already 
remarked,  to  heat,  sound,  light,  etc.,  equivalent  in  amount 
to  the  lost  energy  of  motion.  But  if  it  does  not  fall  down 


MATTER  AND   ENERGY  59 

again — if,  at  the  height  of  its  path  through  the  air,  it  lands, 
for  instance,  upon  a  ledge  of  rock,  no  fresh  manifestations 
of  energy  are  set  up.  Its  kinetic  energy  of  motion  is  lost 
at  the  height  of  its  trajectory ;  it  comes  lightly  or  im- 
perceptibly to  rest  on  the  ledge,  setting  up  very  little  heat 
or  other  phenomena  of  energy.  What  has  happened  to 
the  vanished  energy  of  its  motion  ? 

In  point  of  fact,  it  has  vanished  as  regards  any  actual 
form.  All  that  remains  is  a  latent  power  to  give  out  again 
the  same  amount  of  energy  that  is  apparently  lost.  The 
stone  may  rest  upon  that  ledge  for  an  indefinite  period,  but  if 
the  ledge  is  some  day  removed,  the  stone,  in  falling  to  its 
original  level,  will  give  out  precisely  the  same  amount  of 
energy  originally  conveyed  to  it  when  it  was  projected  by 
the  thrower.  From  the  point  of  view  of  the  thrower,  energy 
vanished  out  of  existence  when  the  stone  came  to  rest  upon 
the  ledge.  From  the  point  of  view  of  the  man  who,  perhaps 
centuries  later,  removes  the  ledge,  energy  suddenly  develops, 
apparently  out  of  nothing.  When,  therefore,  we  speak  of 
the  permanent  indestructibility  and  uncreatibility  of  energy, 
we  are  not  referring  solely  to  kinetic  energy,  which  implies 
something  actually  moving ;  we  include  also  potential  energy, 
where  nothing  whatever  is  occurring,  but  where,  under 
certain  circumstances,  we  know  that  actual  energy  may 
be  produced,  and  we  can  prophesy  the  exact  quantity  of  it. 
In  such  cases  the  energy  is  not  destroyed ;  it  is  in  abeyance 
only.  It  is  spoken  of  as  stored  energy  or  locked-up  energy, 
which  by  suitable  means  can  be  reconverted  into  live  energy 
once  more, 

There  are  many  forms  of  potential  energy  besides  that 
named  above,  which  is  energy  due  to  position.  A  com- 
pressed spiral  spring,  for  instance,  possesses  potential  energy  ; 
so,  also,  a  compressed  gas  or  a  stretched  piece  of  elastic. 
Chemical  affinity  is  a  form  of  potential  energy.  The  radiant 
heat  and  light  of  the  Sun  falling  upon  the  Earth  many  ages 


60    MODERN  SCIENCE  AND  MATERIALISM 

ago  were  caught  up  and  entangled  by  the  then-existing 
vegetation,  and  used  for  building  up  large  complex  organic 
molecules  out  of  simple  inorganic  molecules.  The  radiant 
energy  is  stored  in  these  organic  molecules,  until  the  vegeta- 
tion petrifies  into  coal.  By  burning  the  coal,  the  energy 
which  has  for  so  long  been  locked  up  is  given  forth  afresh 
in  its  original  form  of  heat  and  light. 

Energy,  therefore,  cannot  be  regarded  as  an  actual  existence 
or  a  thing,  notwithstanding  that  it  endures  permanently 
and  is  amenable  to  precise  quantitative  measurement,  and, 
indeed,  is  bought  and  sold  at  fixed  rates  for  commercial 
purposes.  It  has  many  analogies  with  a  thing,  but  it  is  not 
a  thing;  for  it  can  pass  out  of  real  existence,  leaving  no 
trace  behind  it  except  the  power  to  return.  In  the  last 
analysis  it  may,  perhaps,  be  defined  as  that  which,  under  given 
circumstances,  is  capable  of  setting  up  a  sense-impression 
within  us.  Reduction  of  all  phenomena  to  sense-impressions 
is  the  climax  of  scientific  effort. 

Energy  is  generally  regarded  as  consisting  of  two  compo- 
nents— an  extensity  factor  and  an  intensity  factor.  Thus, 
the  energy  of  motion  is  made  up  of  the  momentum  or 
"quantity  of  motion  "  of  the  body  in  question  and  its 
velocity.  The  product  of  these  two  gives  the  kinetic  energy. 
Electrical  energy  is  derived  from  the  "  quantity  of  electricity  " 
and  the  potential.  Heat  is  derived  from  "  entropy "  and 
temperature.  The  same  two  factors  are  found  in  all  forms  of 
potential  energy ;  thus  the  energy  of  position  is  compounded 
from  the  weight  and  the  height  of  the  body  concerned. 
This  mode  of  regarding  energy  as  the  product  of  two  factors 
does  not  appear  to  lead  to  any  very  interesting  results, 
with  the  possible  exception  of  this :  that  there  seems  to 
be  a  general  tendency  throughout  the  Universe  at  present 
towards  a  diminution  of  the  intensity  factor  of  energy, 
and  a  consequent  increase  of  the  extensity  factor.  This 
circumstance  may  now  introduce  us  to  one  of  the  deepest 


MATTER  AND  ENERGY  61 

and  most  significant  of  the  wider  laws  of  philosophical 
physics. 

We  have  pointed  out  that  the  sum-total  of  matter  and 
energy  in  the  Universe  remains  unaltered.  Everything  that 
happens  is  comprised  in  a  mere  redistribution  of  matter  and 
energy,  matter  changing  from  one  form  into  another, 
energy  likewise  changing  its  form,  but  the  actually  existing 
quantity  of  both  remaining  constant.  The  question  now 
arises  whether  these  transformations  of  matter  and  energy 
are  equally  ready  to  take  place  in  any  direction,  or  whether 
they  seem  on  the  whole  to  be  tending  towards  a  goal  in  one 
particular  direction.  If  transformations  of  matter  and 
energy  are  entirely  reversible,  taking  place  with  equal  facility 
in  any  direction,  then  the  Universe  might  be  regarded  as 
a  permanent  existence,  in  more  or  less  its  present  form. 
There  would  be  no  reason  for  supposing  that  it  could  ever 
have  had  a  beginning,  or  that  it  would  ever  have  an  end.  But 
if  the  transformations,  or  (stated  more  simply)  the  events 
occurring  in  the  Universe,  take  place  on  the  whole  in  one 
direction  rather  than  another,  then  there  must  ultimately  be 
reached,  if  the  process  continues,  an  end  to  the  Universe  as 
we  know  it ;  and,  by  similar  reasoning,  there  must,  at  one 
time  or  another,  have  been  a  beginning. 

The  progress  of  physics  has  not  left  the  matter  in  any 
doubt  at  all.  Transformations  do  not  take  place  equally 
readily  in  all  directions ;  they  tend  very  unmistakably 
towards  what  may  be  called  a  degradation  of  matter  and 
energy.  The  Universe  is  running  down  ;  and,  theoretically 
at  least,  a  time  may  be  imagined  when  it  will  have  run  down 
altogether,  becoming  still  and  "  lifeless."  As  regards  energy, 
this  fact  was  discovered  many  years  ago ;  as  regards  matter, 
the  discovery  is  very  recent;  we  shall,  therefore,  deal  first 
with  energy. 

In  every  transformation  of  energy  from  one  form  into 
another  evolution  of  heat  takes  place.  At  every  conversion 


62    MODERN  SCIENCE  AND  MATERIALISM 

of  kinetic  into  electrical  energy,  or  electrical  into  kinetic 
energy ;  of  electrical  energy  into  light ;  of  light  into  chemical 
energy,  and  so  on,  some  wastage  takes  place  in  the  form  of 
heat.  In  all  conversions  of  energy  in  practical  life,  a  leakage 
of  heat  occurs  throughout  the  process.  If,  for  instance,  we 
desire  to  illuminate  a  house  by  the  usual  method  of  convert- 
ing an  electric  current  into  light,  however  perfect  our 
installations,  the  amount  of  light  obtained  is  always,  and 
necessarily,  less  than  the  full  equivalent  of  the  electrical  energy 
supplied.  And  the  reason  is  this,  that  part  of  our  electrical 
energy  inevitably  goes  into  heat,  and  is  not,  therefore, 
entirely  available  for  conversion  into  light.  Every  energy- 
conversion  is,  as  it  were,  attended  with  a  friction,  so  that 
part  of  the  original  energy  is  dissipated  in  the  form  of  heat, 
while  only  the  remainder  is  available  as  utilizable  energy. 
The  amount  of  heat-leakage  varies  widely  in  different 
machines.  The  ordinary  steam-engine,  for  instance,  is  a 
machine  for  converting  chemical  into  kinetic  energy.  The 
chemical  energy  is  contained  in  the  fuel  supplied  to  the 
machine.  By  burning  the  fuel,  the  chemical  energy  is 
changed  into  heat ;  the  heat  again  is  changed  into  pressure 
of  steam ;  and  the  pressure  into  kinetic  energy  or  mass 
motion.  But  the  motion  thus  obtained  through  the  steam- 
engine  is  far  less  than  the  original  energy  supplied  to  it  as 
fuel.  During  the  processes  of  transformation,  at  least  80  per 
cent,  of  the  original  energy  radiates  away  as  heat,  leaving 
only  the  remaining  20  per  cent,  to  be  applied  to  the  purpose 
for  which  the  steam-engine  was  constructed.  In  other  kinds 
of  machines,  as,  for  instance,  a  dynamo,  the  heat  wastage  may 
be  reduced  to  less  than  10  per  cent,  of  the  original  energy  ; 
but  in  every  artefact  machine,  and  in  every  case  of  energy- 
conversion  in  Nature,  some  part  of  the  original  energy  goes 
into  the  form  of  heat.  This  effect  is  not  to  be  regarded  as 
due  to  any  "imperfection"  in  the  processes  of  energy-con- 
version. It  is,  on  the  contrary,  one  of  the  most  fundamental 


MATTER  AND  ENERGY  63 

of  the  laws  of  Nature.  The  dissipation  of  energy  as  heat  is 
as  essential  a  factor  in  natural  processes  as  are  inertia  and 
friction.  Heat,  so  to  speak,  is  the  lowest-grade  form  of 
energy,  to  which  all  other  forms  tend  gradually  to  fall. 

It  was  remarked  just  now  that  all  forms  of  energy  have 
an  intensity  and  an  extensity  factor.  In  the  case  of  heat, 
the  intensity  factor  is  what  we  know  as  temperature;  the 
extensity  factor  is  called  "entropy"  —  a  mere  abstraction, 
representing  no  actual  objective  phenomenon.  Since  a  body 
at  high  temperature  tends  to  convey  heat  to  a  body  at  low 
temperature,  and  since  a  body  at  low  temperature  cannot, 
under  any  circumstances  whatever,  convey  heat  to  a  body 
at  higher  temperature,  there  is  a  further  tendency  to 
universal  equalization  of  temperature.  So  that  the  increase 
in  the  total  quantity  of  heat  does  not  make  its  appearance 
so  much  as  regards  the  intensity  factor  of  temperature,  but 
as  regards  the  extensity  factor  of  entropy.  This  is  expressed 
in  the  statement  that  the  final  goal  to  which  the  Universe 
is  tending  is  that  where  entropy  reaches  a  maximum.  In 
simpler  words,  all  forms  of  energy  are  undergoing  gradual 
degradation  into  heat ;  and  the  heat  so  produced  tends  to 
spread  itself  at  a  level  temperature  throughout  the  entire 
confines  of  the  Universe.  The  goal  to  which  the  Universe 
is  slowly  progressing  is  a  condition  in  which  no  further 
available  energy  is  left,  nor  any  differences  of  tempera- 
ture, but  a  relatively  still,  lifeless,  inert,  cool  aggregation  of 
matter.  •"  0-l$/'" 

After  ascertaining  that  energy  tends  to  a  final  state  of 
universal  degradation,  the  question  naturally  arises  whether 
there  may  not  be  any  corresponding  process  to  be  discovered 
as  regards  matter.  Does  matter,  like  energy,  tend  to  a 
lifeless  equality  throughout  the  Universe  ?  In  this  connec- 
tion we  have  to  consider,  not  the  molecules,  but  the  atoms. 
On  the  Earth,  at  the  present  time,  molecules  are  perhaps  as 
complex  and  as  varied  as  they  have  ever  been.  But  the 


64    MODERN  SCIENCE  AND  MATERIALISM 

molecules  of  highest  complexity  are  those  found  in  living 
organisms,  and  are,  therefore,  purely  ephemeral.  In  a  greater 
or  lesser 'number  of  years,  these  complex  molecules  break  up 
into  simple  molecules  once  again  ;  they  have  no  stability  or 
permanence ;  for  in  such  periods  as  we  have  to  consider,  a 
few  years,  even  a  few  ages  by  human  reckoning,  scarcely 
constitute  a  fleeting  second  in  the  onward  march  of  time. 
Inorganic  molecules  likewise  have  only  a  relative  stability. 
Even  in  an  ordinary  chemical  laboratory  they  can  all  be 
broken  down  into  the  different  elements  of  which  they  are 
composed.  The  question  of  the  permanence  of  matter,  in  its 
present  form,  is  therefore  the  question  of  the  permanence  of 
the  ninety-two  different  kinds  of  atoms  of  which  all  matter 
is  composed. 

Until  recently,  it  was  imagined  that  atoms  were  character- 
ized by  complete  permanence  and  stability.  Modern  re- 
searches in  radio-activity  have  altogether  dissipated  this 
belief.  Sundry  different  atoms  have  been  found  to  be  in 
a  state  of  disintegration.  Atoms  are  composed,  as  already 
explained,  of  a  varying  number  of  electrons,  and  in  those 
atoms  which  are  disintegrating,  single  electrons  are  shot 
forth  into  space,  the  atom  which  remains  being  thereby 
a  smaller  and  less  complex  structure  than  the  original.  The 
atoms  known  to  be  disintegrating  are  the  largest  and  heaviest 
among  the  series  of  ninety-two.  The  largest  atom  of  all — 
that  of  uranium — is  very  slowly  breaking  down  to  form  a 
smaller  and  lighter  atom,  that  of  radium.  The  speed  of 
its  disintegration  is  invariable,  and  cannot  be  altered  or 
affected  in  the  slightest  degree  by  any  agency  known  to  man, 
or  in  whatever  circumstances  it  may  be  found.  The  total 
quantity  of  uranium  on  the  Earth  is  diminishing,  and  the 
most  complex  of  the  elements  is  thus  slowly  but  inexorably 
vanishing  from  our  planet.  Radium  itself  is  still  a  very 
heavy  atom,  but  it,  too,  is  breaking  down,  even  faster  than 
uranium.  Supposing  no  fresh  radium  were  formed,  the  total 


MATTER  AND  ENERGY  65 

amount  of  it  now  on  the  Earth  would  be  reduced  to  one-half 
in  less  than  2000  years.  Radium,  on  breaking  down,  gives 
rise  to  various  new  products  of  highly  unstable  character. 
They  are  all  more  or  less  ephemeral,  having  an  average  life 
varying  from  a  few  years  to  a  few  minutes.  As  these,  one 
after  the  other,  break  down,  the  simplified  atom  that  remains 
at  the  end  is  no  other  than  the  atom  of  the  metal  lead.  It 
is  about  13  J  per  cent,  lighter  than  the  uranium  from  which 
it  was  derived. 

The  chief  popular  interest  of  this  astonishing  discovery 
has  been  in  the  proof  which  it  afforded  of  an  actual  transmu- 
tation of  the  elements.  It  is  genuine  alchemy  going  on  in 
Nature,  though  an  alchemy  which  no  human  agency  is  com- 
petent either  to  accelerate  or  retard.  For  our  present  purpose, 
however,  its  main  interest  is  in  showing  that,  on  the  Earth, 
matter  is  undergoing  a  gradual  simplification.  All  known 
elements  heavier  than  lead  are  disintegrating.1  The  quantity 
of  them  upon  and  within  the  Earth  is  diminishing  by  an 
apparently  irresistible  law.  Nor  is  there  any  reason  to 
suppose  that  this  degradation  of  matter  is  in  progress  only 
among  the  heaviest  atoms,  where  its  operation  is  the  most 
easily  discerned.  A  feeble  radio-activity  has  been  discovered 
in  comparatively  light  and  simple  atoms,  such  as  those  of 
potassium  and  rubidium.  Lately  even  nitrogen  has  been 
found  to  disintegrate,  with  the  formation  of  hydrogen  atoms. 
There  is  very  good  reason  for  the  suspicion  that  all  the 
known  elements  may  be  breaking  down  into  simpler  forms. 
The  disintegration  of  radium  proceeds,  not  only  by  ejection  of 
electrons  from  the  atom  of  radium,  but  also  by  ejection  of 
intact  atoms  of  helium,  which,  after  hydrogen,  is  the  lightest 
known  atom.  One  ounce  of  radium  throws  out  these  helium 
atoms  at  the  rate  of  over  a  thousand  million  a  second.  They 
are  ejected  with  prodigious  force  at  a  velocity  often  greater 
than  ten  thousand  miles  a  second,  and  may  travel  through 

1  Except  bismuth,  which  is  almost  the  same  weight  as  lead. 
F 


66    MODERN   SCIENCE  AND  MATERIALISM 

two  or  three  inches  before  they  come  to  rest.  The  internal 
explosion  by  which  these  helium  atoms  are  driven  forth  is 
inconceivably  more  violent  than  anything  of  the  nature  of 
human  explosives.  The  transformation  of  a  single  ounce  of 
radium  into  its  end-products  would  give  out  as  much  heat  as 
would  be  generated  in  the  combustion  of  fourteen  tons  of 
coal.  It  is  little  wonder  that  these  colossal  forces  are  beyond 
the  control  of  laboratory  methods. 

The  phenomena  of  radio-activity  have  only  been  studied 
on  the  Earth  ;  and  it  does  not  follow  that,  because  on  the 
Earth  matter  is  tending  to  simplification  and  loss  of  variety, 
the  same  processes  need  be  taking  place  in  other  parts  of  the 
Universe.  On  the  contrary,  it  seems  quite  probable  that  at 
the  centres  of  many  stars,  where  the  pressure  and  the  heat 
are  fabulous  in  their  immensity,  a  regeneration  of  atoms  may 
be  in  progress,  and  a  reverse  process  to  that  occurring  on  the 
Earth  may  be  taking  place.  But  the  stars  also  are  radiating 
their  heat  into  space ;  in  course  of  immense  ages  they  cool 
down,  they  reach  the  phase  in  which  we  find  the  Earth  at 
present,  and  they  continue  onwards  to  the  coldness  of  death. 
It  may  well  be  imagined,  therefore,  that  a  similar  degrada- 
tion of  matter  will  then  take  place  in  them  also.  As  heat 
radiates  away  into  space,  matter  becomes  more  and  more 
degraded,  until,  when  all  the  energy  of  the  Universe  is 
reduced  to  an  equal  and  inert  level  of  heat,  matter  itself 
would  also  have  assumed  a  form  very  different  from  that  in 
which  we  now  know  it. 

It  will  be  interesting  to  mark  the  final  goal  to  which  all 
these  natural  processes  are  tending.  There  is,  indeed,  not 
the  smallest  reason  to  believe  that  this  goal  will  ever  be 
reached.  Our  observations  are  limited  to  portions  of  space 
and  time  that  are  infinitesimal  by  comparison  with  the  spaces 
and  times  in  the  life  of  a  universe.  Moreover,  innumerable 
other  factors  must  be  at  work  to  modify  or  reverse  the  ten- 
dencies which  we  can  witness.  While,  therefore,  it  is  not 


MATTER  AND  ENERGY  67 

within  the  horizon  of  humanity  to  prophesy  an  end  to  the 
Universe,  it  is  nevertheless  legitimate  to  point  out  the  end  to 
which  all  things  appear  to  be  moving  in  the  present  state  of 
our  knowledge  and  under  the  extraordinary  limitations  of  our 
observation.  For  things  do  appear  to  be  moving  to  a  goal. 
The  Universe  is  not  reversible,  it  cannot  move  backwards  as 
well  as  forwards ;  it  seems  to  approach  an  end,  when  both 
matter  and  energy  shall  have  reached  their  final  stage  of 
degradation.  Their  gradual  approach  to  that  end  is  not 
such  as  to  suggest  that  it  can  ever  actually  be  attained.  It 
is  an  end  to  which  we  slowly  draw  nearer,  without  ever 
reaching  it,  as  the  curve  of  a  hyperbola  draws  always  nearer 
to  its  asymptote.  The  final  goal  can  never  be  reached, 
because  the  time  taken  to  arrive  there  is  too  inconceivably 
great  even  by  the  standards  of  Astronomy.  It  is,  in  short, 
an  infinite  time  that  would  be  required. 

But  this  goal,  which  can  scarcely  be  the  true  goal,  and 
which  (if  it  were)  could  never  be  absolutely  attained, 
represents  a  condition  in  which  both  matter  and  energy  have 
reached  their  last  degree  of  degradation.  Energy  would 
be  distributed  with  absolute  equality  throughout  every 
corner  of  the  Universe,  in  the  form  of  heat  where  there  was 
nowhere  any  variation  of  temperature.  Matter  would  con- 
sist only  in  the  form  of  the  simplest  known  atoms,  such  as 
those  of  hydrogen  or  of  helium.  Since  heat  is  simply 
molecular  motion,  the  Universe  would  then  consist  only  of 
these  primitive  atoms  in  a  state  of  vibration.  But  is  it  to 
be  supposed  that  even  the  most  primitive  atoms  are  eternally 
stable?  Such  an  atom  consists  typically  of  a  charge  of 
negative  electricity  revolving  at  immense  velocity  around  an 
equal  charge  of  positive  electricity.  Suppose  that  in  course 
of  unimaginable  ages  there  occurs  some  retardation  in  the 
velocity  of  the  negative  electrons,  as  indeed  occurs  with 
planets  revolving  round  a  sun.  What  would  happen  then  ? 
The  same  as  happens  in  a  solar  system,  where  the  planets 


68    MODERN  SCIENCE  AND  MATERIALISM 

at  length  fall  in  upon  their  central  nucleus  of  attraction. 
The  electrons  would  fall  in  upon  the  positive  nucleus,  and 
there  would  remain — nothing  whatever,  no  trace  left  of 
either  energy  or  matter.  For  the  negative  charge,  of  which 
the  electrons  consist,  precisely  neutralizes  the  positive  charge 
of  which  the  nucleus  consists.  All  electrical  phenomena 
would  instantly  vanish  ;  matter  and  energy  would  be  extinct ; 
the  void  which  remained  would  be  just  as  though  no  energy 
and  no  matter  had  ever  previously  existed.  At  the  same 
moment,  all  relations  of  space  and  time  would  be  gone.  The 
Universe  would  have  "gone  out"  more  completely  than 
anything  we  can  understand,  leaving  not  even  a  part  of 
space  of  which  it  might  be  said  that  here  the  Universe 
once  existed ;  not  even  a  period  of  time  during  which  it 
might  be  said  that  the  Universe  was  a  real  thing. 

A  few  words  may  be  added  here  concerning  the  relationship 
to  philosophic  materialism  of  modern  views  as  to  the  con- 
stitution of  matter.  These  modern  views  are  in  every  par- 
ticular consonant  with  materialistic  interpretations  ;  they  are 
in  every  particular  irreconcilable  with  spiritualistic  interpre- 
tations. Penetration  into  the  secrets  of  atomic  structure  has 
opened  up  to  us  a  vast  new  sphere  of  phenomena  whose  very 
existence  was  previously  unsuspected,  and  which  differ  toto 
coelo  from  all  kinds  of  phenomena  with  which  we  were 
previously  acquainted.  Yet  throughout  this  new  continent 
of  knowledge  we  find  the  axioms  of  materialism  as  un- 
questioned as  ever.  The  electrons  and  the  positively  charged 
nuclei  of  atoms  have  their  unchangeable  laws,  and  illustrate 
afresh  the  inviolable  relation  of  cause  and  effect.  Nor,  as  we 
approach  the  very  foundations  of  existence,  do  we  see  any 
more  signs  than  elsewhere  of  a  purpose  at  the  basis  of  the 
Universe.  Harmony  and  order,  certainly:  that  arises  from 
the  universality  of  natural  law ;  it  is  the  same  kind  of 
harmony  and  order  that  prevails  in  the  larger  material  masses 
of  the  Universe.  Even  if  the  Universe  is  running  down  to  a 


MATTER  AND   ENERGY  69 

final  doom  of  extinction,  there  is  no  suggestion  of  purpose 
there.  A  clock  also  runs  down,  but  not  by  previous  in- 
tention— not  for  what  we  understand  as  a  purpose.  Finally, 
in  this  new  field  of  discovery  there  is  no  place  for  any  kind 
of  spiritual  agency.  We  know  at  length  what  is  the  basis  of 
matter :  it  is  not  spirit,  it  is  energy,  a  factor  exclusively 
objective  in  character,  and  residing  on  the  materialistic, 
not  on  the  spiritualistic  plane.  It  may  be  suggested  that 
materialism  is  no  longer  a  suitable  name  for  a  doctrine  which 
dissolves  away  all  matter  into  intangible  energy.  The  con- 
tention cannot  be  upheld,  however.  /Scientific  materialism  has 
never  imagined  matter  to  be  as  it  seems  to  the  unaided  touch 
and  vision ;  and  into  whatever  factors  it  may  be  analyzed,  it 
remains  matter  in  the  only  sense  knowable  by  us.  « Heat  is 
none  the  less  heat  that  it  consists  in  molecular  vibration ; 
light  is  none  the  less  light  that  it  is  an  electro-magnetic 
manifestation  in  space ;  nor  is  matter  any  the  less  matter  in 
that  it  may  be  resolved  into  energy  or  even  into  nothing.  It^ 
remains  the  prototype  of  all  that  class  of  phenomena ;  and 
materialism  in  consequence  remains  the  most  suitable  name 
for  the  philosophy  which  embraces  it. 

Furthermore,  one  thing  is  certain.  Whatever  matter  may 
ultimately  be  resolved  into,  it  certainly  cannot  be  resolved 
into  spirit.  The  wildest  speculator  in  science  has  never 
suggested  that  possibility.  And  the  name  materialism  only 
has  a  meaning  by  contrast  with  the  rival  doctrine  of  spirit- 
ualism. We  may,  indeed,  note  the  astonishing  range  of 
materialistic  explanations,  as  compared  with  those  put 
forward  on  the  spiritualistic  side.  These  latter  adopt  the 
commonplace  experiences  of  ordinary  life,  and  transfer  them 
indiscriminately  to  a  new  region.  Whenever  a  difficulty 
arises,  spiritual  agency  is  invoked  to  explain  it.  All  things 
are  regarded  as  the  product  of  a  magnified  but  still  quasi- 
human  intelligence,  working  by  quasi-human,  or  usually 
wholly  human,  motives.  This  single  idea  is  monotonously 


70    MODERN  SCIENCE  AND  MATERIALISM 

repeated  as  often  as  the  need  of  explanation  is  felt,  whereas 
under  the  materialistic  philosophy  a  stream  of  fresh  con- 
ceptions of  unimagined  novelty  continues  to  flow.  The 
wonders  and  the  miracles  of  theological  cosmogonies  become 
dull  and  commonplace  by  comparison  with  the  materialistic 
statement  of  the  actual  facts.  But,  in  truth,  spiritualism 
has  long  been  driven  from  the  sphere  of  the  inorganic.  Its 
last  refuge  is  in  the  sphere  of  life  and  consciousness,  to  which 
accordingly  we  shall  now  turn  our  attention. 


CHAPTER   III 

LIFE    AND    CONSCIOUSNESS 

WE  have  investigated  two  out  of  the  three  fundamental 
classes  of  phenomena  which  appeared  at  our  first  inspection 
to  make  up  the  Universe.  We  have  found  that  these  two — 
matter  and  energy — are  ultimately  reducible  to  one.  We 
now  turn  to  the  third,  in  order  to  ascertain  to  what  extent, 
if  any,  it  differs  from  the  other  two.  Primd  facie  the  pheno- 
mena of  life  and  consciousness  would  appear  to  be  in  an 
entirely  different  category  from  the  phenomena  already 
described.  Realities,  however,  are  very  different  from  primd 
facie  appearances.  Just  as  we  found  that  matter  and  energy 
are  fundamentally  different  from  what  an  uneducated  opinion 
imagines,  so  we  must  be  prepared  to  find  that  life  and 
consciousness  can  be  analyzed  into  altogether  unexpected 
elements.  Unfortunately,  prejudice  in  this  sphere  is  far 
more  universal  than  in  that  hitherto  dealt  with.  Many — 
most  people  in  fact — start  with  a  rooted  determination  that 
life  and  matter  are  essentially  and  necessarily  distinct  from 
one  another.  They  hold  this  belief  before  they  begin  to 
inquire  into  the  subject,  and  they  hold  it  with  such  tenacity 
as  to  close  their  minds  to  all  contradictory  evidence.  If  the 
reader  is  determined  to  harbour  that  particular  opinion,  let 
him  harbour  it,  and  save  himself  the  effort  of  investigation. 
There  is  no  compulsion  upon  him  to  ask  further  on  a  question 
where  his  mind  is  already  made  up.  If,  on  the  other  hand, 
he  really  desires  to  know  the  truth  of  things,  let  him  dismiss 
all  bias  and  start  with  a  genuinely  open  mind,  remembering 
that  science  very  rarely  bears  out  the  first  conclusions  formed 

by  the  uninstructed  imagination. 

71 


72    MODERN  SCIENCE  AND  MATERIALISM 

We  have  found  that  there  exist  upon  the  Earth  ninety -two 
possible  different  kinds  of  atoms,  and  that  from  the  different 
combinations  of  these  atoms,  all  the  different  substances  on 
the  Earth  take  their  origin.  We  found  that  the  inorganic 
substances  are  aggregates  of  molecules,  consisting  for  the 
most  part  of  comparatively  few  atoms.  Organic  substances, 
on  the  other  hand,  are  aggregates  of  molecules,  containing 
usually  a  far  larger  number  of  atoms,  and  they  have  the 
^further  characteristic  that  among  these  atoms,  the  atom  of 
carbon  is  invariably  present.  For  this  reason,  organic  chem- 
istry is,  in  reality,  the  chemistry  of  the  carbon  compounds ; 
and  the  highly  complex  compounds  characteristic  of  carbon 
have  properties  correspondingly  more  complex  than  those  of 
simpler  compounds. 

Of  all  the  carbon  compounds,  the  most  complex  are  those 
which  constitute  the  group  called  protoplasm.  So  complex, 
indeed,  is  this  class  of  substance,  that  it  has  not  yet  been 
given  any  precise  chemical  formula.  It  is  known,  however, 
to  be  a  congeries  of  substances,  of  somewhat  different  con- 
stitution, and  not  a  single  fixed  compound.  The  elements 
of  which  it  consists  are  chiefly  carbon,  oxygen,  hydrogen, 
nitrogen,  sulphur,  phosphorus,  sodium,  potassium,  chlorine, 
calcium,  magnesium,  and  iron.  No  element  enters  into  its 
composition  except  such  as  are  quite  common  in  the  inorganic 
world.  The  most  essential  and  invariable  constituents  of 
protoplasm  are  the  proteins,  the  molecules  of  which  are  known 
to  be  of  immense  complexity,  consisting  certainly  of  hundreds, 
possibly  of  thousands,  of  individual  atoms.  These  protein 
molecules  each  appear  to  be  systems  of  smaller  molecules, 
united  together.  In  the  same  way,  it  is  conceived  that  the 
physico-chemical  unit  of  protoplasm  may  be  a  system  of 
protein  molecules  held  together,  in  conjunction,  perhaps,  with 
molecules  of  carbohydrate  or  fat.  Protoplasm  is  a  name,  not 
for  one  substance,  but  for  a  class  of  substances,  and  the 
special  interest  attaching  to  this  class  of  substances,  is  that  out 
of  them  the  living  tissues  of  animals  and  plants  are  built  up. 


LIFE  AND   CONSCIOUSNESS  73 

Protoplasm  is  found  only  on  or  near  the  surface  of  the 
Earth.  As  a  highly  complex  substance,  it  is  rapidly  dis- 
integrated by  heat  into  its  components,  and  its  formation 
occurs  only  within  narrowly  defined  conditions.  Corre- 
sponding to  its  elaborate  chemical  constitution,  its  physical 
and  chemical  reactions  are  likewise  elaborate.  All  the  mani- 
festations of  living  organisms,  in  short,  are  expressions  of 
the  chemical  reactions  of  protoplasm.  This  extraordinarily 
complex  and  varied  group  is  found  upon  the  Earth  in  a  very 
large  number  of  different  types.  These  types  form  the 
foundation  of  what  are  called  species ;  and  we  now  turn  to  a 
consideration  of  what  actually  constitutes  a  species. 

No  two  individuals,  either  animal  or  plant,  are  precisely 
identical.  But,  on  the  other  hand,  no  individuals  are  found 
that  do  not  bear  a  close  resemblance  to  numerous  other 
individuals.  It  is  thus  possible  to  draw  up  a  classification 
of  animals  and  plants,  based  on  their  resemblances.  The 
unit  of  such  classification  is  the  species,  consisting  of  groups 
of  organisms  all  similar  to  one  another  in  essential  details, 
and  differing  only  in  those  minutice  by  which  individuals  are 
distinguished.  Naturalists  do,  indeed,  establish  groups  still 
narrower  than  species ;  they  classify  organisms  into  sub- 
species and  into  varieties,  but  with  this  we  are  not  now 
concerned.  When  all  animals  are  divided  into  species,  it  is 
found  that  some  species  resemble  one  another  more  than 
others,  and  a  number  of  similar  species  are  bracketed  together 
to  form  a  genus.  So,  too,  genera  are  combined  to  form 
families,  families  to  form  orders,  and  orders  to  form  classes, 
so  that  the  animal  and  plant  kingdoms  are  divided  into  a 
comparatively  small  number  of  classes,  which  comprise  all 
living  organisms  within  them. 

These  various  divisions  of  animate  nature  have  no  real 
existence  as  objective  things.  They  do,  indeed,  represent 
the  family  relationships  of  living  beings,  but  one  of  them 
represents  still  more.  A  species  is  an  actual  entity,  present 
in  Nature  as  a  real  individual  thing,  and  not  merely  a  unit 


74    MODERN  SCIENCE  AND  MATERIALISM 

of  classification.  In  ordinary  biological  usage,  the  word 
connotes  a  sum -total  of  similar  inter-breeding  individuals  on 
the  Earth.  But  in  reality  it  is  more  than  that.  It  is  a 
particular  kind  of  germ-plasm — or  type  of  protoplasm — 
sprawling  at  large  over  the  Earth's  surface,  and  budding  forth 
innumerable  similar  "  individuals "  by  a  process  of  serial 
homology.  It  is  on  the  germ-plasm,  not  on  the  individuals, 
that  we  must  concentrate  attention.  Just  as  protoplasm  is 
one  kind  of  substance  among  many  others  on  the  Earth,  so 
there  are  many  kinds  of  protoplasm.  Each  kind  appears  on 
its  biological  side  as  a  species — the  countless  discrete  particles 
in  which  it  exists  being  kept  in  periodic  communication 
by  a  physical  process  which  again  on  its  biological  side 
appears  as  sexual  reproduction. 

To  explain  how  this  is  so,  we  must  turn  to  the  germ-plasm 
theory  of  Weismann.  Every  individual  organism  begins  its 
life  as  a  single  cell  or  ovum,  a  cell  being  a  microscopic  speck 
of  protoplasm.  In  the  elementary  forms  of  life  it  remains 
a  single  cell  without  further  development,  but  in  all  higher 
forms  it  multiplies  rapidly  to  form  a  colony  or  nation  of 
cells  cleaving  together  to  form  what  we  call  the  individual. 
The  mode  of  multiplication  is  always  the  same  as  regards 
its  more  obvious  features :  the  cell  divides  into  two  cells 
by  a  stricture  appearing  round  its  circumference.  These 
two  daughter-cells  quickly  grow  to  the  size  of  their  parent- 
cell,  and  each  then  divides  again,  so  that  before  long  large 
numbers  of  cells  are  clustered  together.  Moreover,  as  they 
multiply  they  become  differentiated  from  each  other.  Some 
acquire  the  characters  of  muscle-cells,  others  of  nerve-cells, 
and  so  on.  The  higher  the  organism  in  the  evolutionary 
scale,  the  more  complete  is  this  differentiation  between  its 
component  parts.  But  however  high  it  may  be,  there  always 
remain  some  cells  which  are  not  differentiated  along  similar 
lines  to  the  rest,  but  retain  the  primitive  protoplasmic 
characters  of  the  original  ovum.  From  these  undifferentiated 
cells  new  individuals  can  blossom  forth ;  they  are  the  germ- 


LIFE  AND   CONSCIOUSNESS  75 

cells,  and  are  called  by  Weismann  the  germ-plasm,  while  the 
body-cells  which  have  become  differentiated  are  called  the 
soma-plasm,  and  have  largely  lost  the  power  to  produce  other 
cells,  except  such  as  are  differentiated  like  themselves. 

All  multicellular  animals  and  plants  consist,  therefore, 
biologically  of  two  main  parts — germ-plasm  and  soma-plasm. 
Of  these  the  soma-plasm,  by  far  the  bulkier  portion,  is 
perishable,  and  after  a  longer  or  shorter  period  undergoes 
the  disintegration  of  death.  The  germ-plasm,  on  the  contrary, 
is  not  liable  to  death  in  the  same  way.  It  is  relatively 
immortal.  Each  generation  springs  from  the  germ-plasm  of 
its  parents,  so  that  a  thread  of  actual  physical  continuity 
connects  each  generation  from  the  very  beginning  of  evolution 
down  to  the  present  time.  The  germ-plasm  of  any  individual 
is  the  very  same  germ-plasm  as  that  of  his  ancestors  thousands  , 
or  millions  of  generations  back.  It  has  been  incessantly 
dividing  in  two  all  the  time,  and  the  vast  mass  of  its  products 
have  either  developed  into  somata  or  been  cast  away  and 
lost.  But  the  germ-cell,  from  which  every  individual  takes 
his  origin,  is  a  real  physical  portion  of  that  germ-plasm 
which  made  up  the  bodies  of  his  protozoan  ancestors,  perhaps 
many  hundred  million  years  ago,  and  which  has  survived 
through  an  infinity  of  generations,  and  undergone  immense 
modifications  ever  since.  Thus  the  life  of  a  species  is  the 
life  of  its  germ -plasm,  and  the  species  only  becomes  extinct 
when  the  germ-plasm  of  it  dies.  The  existence  of  a  species 
is  far  more  than  a  mere  symbol  in  the  terminology  of 
classification.  It  represents  an  actually  living  germ-plasm, 
one  type  of  protoplasm,  or,  in  other  words,  a  substance  of 
definite  chemical  properties  existing  on  the  surface  of  the 
Earth.  So  long  as  that  substance  continues  to  exist,  the 
species  which  it  represents  continues  to  survive. 

A  species,  therefore,  is  a  more  real  unit  of  classification 
than  is  a  genus  or  an  order,  which  represent  no  objects 
existing  upon  the  Earth,  but  merely  indicate  a  resemblance 
between  objects.  If  we  wish  to  obtain  an  idea  as  to  the 


76    MODERN   SCIENCE   AND   MATERIALISM 

(fundamental  facts  of  life,  we  must  consider  it  from  the  point 
of  view,  not  of  individuals,  but  of  species.  For  an  individual 
is  simply  an  outgrowth  upon  a  fragment  of  germ-plasm.  It 
is  a  highly  perishable  excrescence,  which  protects  and  sub- 
serves the  continuance  of  the  germ-plasm  within  it — the 
germ-plasm  being  the  main  fact  of  the  species  itself.  Unfortu- 
nately we  are  individuals,  and  our  first  outlook  is  naturally 
from  the  point  of  view  of  individuals.  But  this  anthro- 
pocentric  outlook  has  to  be  altered,  if  facts  are  to  be  seen 
in  their  correct  perspective. 

We  start,  then,  from  the  basis  that,  in  addition  to  the  very 
large  variety  of  inorganic  substances  found  upon  the  earth, 
there  are  an  immense  number  of  the  so-called  organic  sub- 
stances, which  are  carbon  compounds  of  high  molecular 
complexity.  Carbon  enters  into  so  immensely  wide  a  range 
of  combinations,  that  the  study  of  its  compounds  is  one  of 
the  most  important  fields  of  chemical  science.  And  among 
the  most  complex  of  these  compounds  are  the  innumerable 
types  of  protoplasm.  To  the  chemist  they  differ  from  other 
substances  only  by  virtue  of  the  large  number  of  atoms 
contained  in  their  molecules,  so  that  they  are  the  most 
complex  substances  with  which  he  has  to  deal.  The  biologist 
calls  them  species,  whether  of  animal  or  plant.  Their 
chemical  properties  are  complex  in  proportion  to  their 
structure.  Those  same  properties  are  recognized  by  the 
biologist  in  the  functions  of  animals  and  plants ;  in  their 
modes  of  growth  and  reproduction ;  in  their  instincts,  and 
even  in  their  intelligence,  their  emotions,  and  their  will. 

We  have,  then,  first  to  inquire  into  some  of  the  more 
singular  properties  of  protoplasm.  We  note  that  it  exists 
in  the  form  of  cells,  which  increase  in  size  by  internal 
absorption.  Inorganic  substances  are  similarly  found  in 
discrete  masses  of  specific  structure,  known  as  crystals  ;  but 
they  increase  in  size  by  external  accretion.  The  tendency  to 
grow  out  into  a  specific  form  is  specially  characteristic  of 
protoplasm.  The  germ-plasm  of  any  species  buds  out 


LIFE  AND   CONSCIOUSNESS  77 

innumerable  homologous  excrescences  upon  itself,  all  very 
similar  to  one  another,  like  the  leaves  on  a  tree.  These 
excrescences  are  the  individuals  who,  taken  collectively,  make 
up  the  species  as  it  appears  to  man.  But  the  germ-plasm 
or  protoplasmic  substance  slowly  alters  in  constitution  :  it 
undergoes  variation.  What  this  variation  consists  in,  is 
not  known,  but  its  results  are  visible  in  the  different  types 
of  excrescence  which  it  grows  upon  itself.  This  change  of 
character  may  in  the  course  of  ages  attain  a  very  far- 
reaching  effect.  The  germ-plasm  of  man,  for  instance, 
countless  ages  ago  did  not  produce  what  we  should  now 
recognize  as  a  man,  but  a  creature  more  like  an  ape.  Still 
earlier,  it  grew  upon  itself  a  fish-like  animal,  which  swam  in 
the  water ;  nor  has  it  yet  altogether  lost  the  traces  of 
this  property,  for  the  human  foetus  at  a  certain  stage  of 
development  still  has  gill-slits,  which  occasionally  persist 
even  up  to  birth.  Far  earlier  still,  the  human  germ-plasm 
grew  upon  it  individuals  even  more  unlike  what  it  grows 
now,  until  right  back  near  the  origin  of  life  it  had  no  power 
to  grow  an  excrescence  at  all,  but  lived  as  a  single  cell 
in  a  free  and  independent  life.  Even  of  these  early  stages 
some  traces  still  remain.  The  proportion  of  sodium, 
potassium,  and  calcium  ions  in  sea- water  and  in  blood-serum 
are  almost  identical ;  but  the  total  concentration  is  higher 
in  sea-water,  for  the  sea  has  become  more  salt  since  it 
circulated  in  the  body  of  the  earliest  ancestors  of  man. 
The  germ-plasm  thus  slowly  changes  its  constitution  in 
course  of  vast  ages.  It  is  physically  the  same  germ-plasm, 
though  its  chemical  and  physical  properties  have  undergone 
alteration.  The  biological  counterpart  of  this  phenomenon 
is  evolution.  It  is  to  be  noted,  however,  that  the  slow 
modification  in  the  structure  of  protoplasm  is  paralleled  by 
modifications  in  the  structure  of  inorganic  substances.  We 
have  already  seen  how  the  more  complex  atoms  are  slowly 
built  up  or  disintegrated  under  different  conditions  of  the 
environment.  Similarly,  complex  molecules  exist  in  one 


78    MODERN  SCIENCE  AND  MATERIALISM 

state  of  the  Earth's  surface,  but  have  changed  their 
constitution  in  another  state.  The  properties  of  protoplasm 
differ  from  the  properties  of  an  inorganic  substance  only_as 
its  chemical  and  physical  constitution  is  different  from  theirs. 

A  more  singular  feature  of  protoplasm,  and  one  which 
removes  it  still  further  from  other  kinds  of  substances  on  the 
Earth,  is  that  which  on  its  biological  side  appears  as  sexual 
reproduction.  This  is  a  contrivance  by  which  the  germ- 
plasm  of  a  species,  normally  broken  up  into  a  large  number 
of  separate  portions,  preserves  a  continuity,  each  separate 
portion  being  merged  at  intervals  in  another  portion,  so  that 
the  entire  germ-plasm  retains  a  physical  unity,  in  the  sense 
that  no  single  portion  can  live  in  isolation  from  the  rest  for 
more  than  a  certain  period  of  time.  The  essential  fact  about 
sexual  reproduction  is  the  fusion  of  two  germ-cells  together, 
these  cells  nearly  always  emanating  from  different  individuals. 
A  human  analogy  will  indicate  how  effective  this  process  is 
in  achieving  the  unification  of  species  by  merging  each 
isolated  fragment  in  the  common  stock  at  definite  intervals. 

Every  man  has  two  parents,  four  grand-parents,  eight 
great-grand-parents,  and  so  on  in  geometrical  series,  so  long 
as  no  intermarriages  have  taken  place.  On  this  condition, 
the  number  of  his  ancestors  in  the  tenth  generation  back  will 
be  1024.  On  going  back  as  far  as  the  twenty-first  generation, 
and  still  supposing  that  no  intermarriages  have  occurred,  the 
number  of  his  ancestors  in  that  generation  alone  will  exceed 
two  millions.  If  we  reckon  a  generation  at  thirty  years,  we 
conclude  that  six  hundred  years  ago  the  number  of  persons 
then  existing  who  have  borne  a  part  in  the  production  of  our 
own  individual  body  exceeded  two  millions.  But  less  than 
six  hundred  years  ago,  when  the  Black  Death  had  ravaged 
the  country  from  end  to  end,  the  whole  population  of 
England  probably  did  not  exceed  two  millions.  On  the 
supposition,  therefore,  that  there  have  been  no  inter- 
marriages and  no  admixture  of  foreign  blood,  we  must  each 
represent  in  our  own  body  the  germ-plasm  and  characteristics 


LIFE  AND   CONSCIOUSNESS  79 

of  the  entire  population  of  England  less  than  six  centuries 
ago !  Six  centuries  is  a  long  period  by  the  standards  of 
individual  life,  but  it  is  as  nothing  in  the  life  of  the  germ- 
plasm — in  the  history  of  the  species.  We  see  that  in  the 
course  of  these  centuries  there  has  taken  place  a  complete 
pooling  of  the  germ-plasm  of  the  population,  so  that  every 
living  individual  is  related  to  every  other  individual  by 
physical  continuity  of  germ-plasm  at  no  very  distant  period 
of  time. 

The  case  is  the  same  if,  instead  of  tracing  the  generations 
backwards  into  the  past,  we  trace  them  forwards  into  the 
future.  If  the  numbers  of  the  population  were  to  remain 
stationary,  and  other  conditions  are  as  before,  a  man  may 
expect  that  his  living  progeny  in  six  hundred  Years'*  time  will 
exceed  two  millions.  From  these  two  examples,  we  see  the 
everlasting  process  of  diffusion  and  re-integration  of  the 
germ-plasm.  In  the  first  example,  the  scattered  germ-plasms 
of  two  million  persons  have  united  in  the  production  of  one  ; 
in  the  second  example,  the  germ-plasm  of  one  individual  has 
diffused  into  the  inheritance  of  two  millions.  It  is  mere 
fancy  for  any  one  to-day  to  point  out  a  definite  individual 
several  centuries  back  as  "his  ancestor.'1  The  people  of 
to-day  are  in  a  body  the  children  of  the  people  of  ancient 
times.  The  heredity  has  been  completely  diffused  and  inter- 
mingled ;  so  that,  going  back  some  centuries,  it  would 
be  much  harder  to  find  a  man  who  was  not  our  ancestor 
than  one  who  was,  excluding  persons,  of  course,  whose 
descendants  have  altogether  died  out. 

We  thus  reach  a  new  conception  of  species.  The  germ- 
plasm,  or  physical  sub-stratum  of  the  species,  exists,  like 
other  substances  upon  the  Earth,  in  discrete  fragments 
scattered  at  large.  But,  unlike  those  other  substances,  the 
discontinuity  is  not  absolute.  Each  separate  fragment  is 
merged  from  time  to  time  in  the  common  stock.  The 
germ-plasm  of  any  species  has  a  unity  and  individuality 
of  its  own.  By  a  rough  analogy  it  may  be  compared  to 


80    MODERN  SCIENCE  AND  MATERIALISM 

a  network,  each  knot  representing  a  soma  or  individual 
budded  forth  from  it.  Two  separate  strands  unite  to  form 
the  knot,  and  from  it  spring  on  the  average  two  separate 
strands  again.  The  analogy  is  exceedingly  imperfect,  for 
a  network  is  an  existence  in  space,  and  we  are  dealing 
rather  with  a  phenomenon  in  time.  It  serves,  however,  to 
illustrate  the  fact  that  direct  physical  continuity  exists  in 
a  sense,  or  has  existed,  between  every  individual  member 
of  a  species.  By  going  back  far  enough,  we  can  travel 
from  any  one  knot  to  any  other  knot  by  a  complete 
succession  of  strands  :  between  any  two  individuals  of  a 
species  there  exists  a  protoplasmic  linkage  which,  though 
it  may  be  remote,  is  never  broken  by  a  discontinuity.  A 
striking  difference,  therefore,  between  protoplasm  and 
simpler  substances,  is  that  the  various  types  of  protoplasm 
found  on  the  earth,  and  representing  the  various  species, 
each  constitute  an  organic  unity  embracing  all  the  scattered 
particles  that  exist. 

The  reason,  or  rather  the  effect,  of  this  arrangement  is 
obvious.  The  constitution  of  protoplasm  is  subject  to  vari- 
ation. By  incessant  pooling  in  the  common  stock,  individual 
variations  are  merged  in  the  general  germ-plasm.  They 
there  contribute  their  quota  of  modification,  tending  towards 
modification  of  the  species.  But  no  variation  is  likely  to 
remain  permanent,  unless  a  large  number  of  individuals  are 
affected  by  it  or  unless  it  has  a  remarkable  stability  and 
dominance ;  the  resultant  effect  may  then  be  sufficiently 
great  to  influence  the  character  of  the  whole  germ-plasm, 
whereas  a  minor  variation  brought  in  by  only  one  or  two 
individuals  is  likely  to  be  swamped  out  among  the  rest.  In 
short,  the  effect  is  to  limit  the  variability  of  protoplasm. 
By  sexual  reproduction  the  whole  species  preserves  a  com- 
mon constitution ;  it  can  only  vary  en  masse ;  isolated 
departures  from  the  normal  soon  die  out.  Were  it  not  for 
this  arrangement,  animals  and  plants  could  no  longer  be 
classified  into  separate  groups  as  they  are  now.  Every 


LIFE  AND  CONSCIOUSNESS  81 

animal  or  plant  would  have  a  separate  and  independent 
structure  of  its  own.  The  individual,  not  the  species,  would 
be  the  basis  of  life ;  and  instead  of  finding,  as  we  do,  classes, 
orders,  genera,  and  species  marked  off  tolerably  clearly  into 
groups,  we  should  find  the  whole  field  of  biological  vision 
dotted  indiscriminately  with  living  beings  having  every 
imaginable  variety  of  structure  and  of  function,  and  not 
susceptible  of  any  natural  classification. 

As  to  the  causes  of  variation,  nothing  is  known.  We 
merely  perceive  that  protoplasm  is  of  somewhat  indefinite 
constitution,  and  easily  liable  to  modification.  The  actual 
causes  of  that  modification  are  no  more  known  than  the 
causes  of  modification  of  atomic  structure  noted  in  the 
last  chapter.  Certain  phases  of  stellar  evolution  seem  to 
favour  the  development  of  certain  types  of  matter,  which 
disappear  again  when  that  phase  is  past.  One  phase  favours 
the  development  of  protoplasm,  i.e.  the  development  of 
life ;  and  protoplasm,  being  more  complex,  is  more  plastic 
than  other  substances ;  its  elaborate  chemical  and  physical 
constitution  is  very  responsive  to  external  change  and  is 
less  stable  than  that  of  simpler  inorganic  substances. 

Given  the  fact  of  variation,  the  origin  of  species  becomes 
more  intelligible.  It  may  be  that  a  few  individuals  bring 
into  the  common  stock  of  germ-plasm  a  new  variation  of  so 
strong  and  stable  a  character  that  it  cannot  be  swamped  out, 
but  gradually  imposes  itself  upon  the  whole  species.  Or  it 
may  be  that,  by  geographical  or  other  causes,  one  part  of  a 
species  is  cut  off  from  another  part.  Their  germ -plasm  is 
cut  in  twain,  and  each  section  proceeds  to  develop  on  its  own 
lines.  We  thus  have  the  small  differences  between  the 
English  pied  wagtail  and  the  Continental  white  wagtail; 
between  the  English  coal-titmouse  and  the  Irish  coal-tit- 
mouse, and  so  on.  The  two  divisions  of  the  severed  germ- 
plasm  are  starting  on  independent  lines  of  evolution,  owing 
to  a  cessation  of  interbreeding  between  them. 

Protoplasm  exists  in  the  form  of  cells,  or  small  globules  of 


82    MODERN  SCIENCE  AND  MATERIALISM 

jelly-like  consistency.  These  unit-cells  increase  in  size  by 
absorption  of  nutritive  matter  with  which  they  come  in  con- 
tact. As  soon  as  they  have  attained  certain  dimensions,  how- 
ever, they  cease  to  grow,  become  constricted  round  the  middle, 
and  finally  divide  into  two.  The  daughter-cells  so  formed 
go  their  own  way,  grow,  and  then  divide  like  their  parents, 
and  so  on  ad  infinitum.  Primitive  forms  of  life  are  thus 
limited  to  single  cells.  No  soma-plasm  yet  exists,  and  sexual 
reproduction  consists  in  the  fusion  of  two  entire  organisms. 
As  evolution  progresses,  a  change  takes  place.  The  cell  con- 
tinues to  divide  in  two  as  before,  but  the  daughter-cells  are 
incompletely  separated.  Division  and  re-division  continue 
until  a  whole  cluster  of  cells  is  formed,  loosely  held  together 
in  a  single  whole.  At  the  same  time  that  this  new  feature 
makes  its  appearance,  the  cells  themselves  cease  to  be  all  alike, 
but  become  differentiated  both  in  structure  and  in  function. 
Some  become  modified  for  drawing  in  particles  of  food  that 
are  floating  by,  others  become  modified  for  digesting  it ; 
some  function  as  rudimentary  muscles,  others  as  nerves,  and 
so  on.  The  great  majority  undergo  some  kind  of  modi- 
fication. Taken  together  they  form  the  soma  or  body  of 
the  individual.  A  few,  however,  retain  their  primitive 
characters  ;  these  constitute  the  germ -plasm. 

The  single  cell  of  the  original  organism  carries  on  by  itself 
all  the  functions  necessary  to  existence :  nutrition,  growth, 
reproduction,  digestion,  excretion,  etc.  It  possesses  in 
extremely  rudimentary  form  the  properties  of  muscle,  nerve, 
senses,  circulation,  etc.  When,  however,  owing  to  incomplete 
separation,  a  colony  is  formed,  the  somatic  cells  which  become 
specialized  for  definite  purposes  lose  their  original  capacity 
for  fulfilling  other  purposes.  Their  greatly  increased 
capacity  for  some  one  function  involves  a  loss  of  capacity  for 
all  other  functions.  Development  implies  a  great  gain  of  one 
property,  with  a  corresponding  loss  of  all  others.  Among 
the  properties  which  are  lost  are  those  of  producing  any  cells 
unlike  themselves.  A  specialized  cell  usually  reproduces 


LIFE  AND   CONSCIOUSNESS  83 

only  other  specialized  cells  like  itself;  it  ceases,  with  certain 
exceptions,  to  represent  the  whole  properties  of  the  germ- 
plasm.  A  mutual  interdependence  throughout  the  colony  is 
set  up,  and  natural  death  makes  its  first  appearance ;  but 
both  then  and  throughout  evolution,  natural  death  is  an 
attribute  only  of  the  specialized  somatic  cells.  The  germ- 
cells  may,  indeed,  die,  but  they  have  no  inevitable  tendency 
to  death,  for  their  life  is  the  life  of  the  species.  With  the 
further  course  of  evolution,  specialization  and  interdependence 
become  more  and  more  absolute,  until  we  reach  the  higher 
groups  of  vertebrates,  in  which  every  part  of  the  body  is 
marvellously  adapted  to  some  special  requirement  of  the 
animal,  whose  continued  existence  is  dependent  upon  a  close 
inter-relation  of  innumerable  different  specialized  organs  and 
tissues. 

Now,  from  our  narrow  human  point  of  view,  one  of  the 
most  significant  facts  about  an  animal  or  plant  is  what  we 
call  the  purposiveness  which  seems  to  control  its  entire 
organization.  It  seems  to  be  an  enormously  complex  piece 
of  mechanism  designed  for  a  particular  end,  namely,  that  of 
the  preservation  of  the  individual ;  and  this  end  again 
appears  to  be  subservient  to  another  and  a  greater  end,  the 
preservation  of  the  species.  Nearly  every  part  of  the  organism 
is  adapted  for  furthering  the  life  of  the  whole ;  not  quite 
every  part,  indeed,  for  there  are  always  some  structures  and 
some  functions  which  neither  are,  nor  ever  have  been,  of  the 
slightest  utility,  but  are  pure  chance  products  and  accidents 
of  evolution.  Taken  altogether,  however,  an  organism  is 
a  highly  teleological  piece  of  apparatus.  In  almost  every 
part  of  it,  adaptation  to  a  definite  end  is  obvious,  and  the 
sum-total  of  adaptations  to  a  single  end  is  so  striking  as 
almost  to  justify  the  term  miraculous.  Little  wonder,  then, 
that  until  recent  times  it  was  supposed  to  be  actually  the 
manifestation  of  a  miracle.  It  was  imagined  that  every 
individual  had  been  specially  created  by  a  being  of  infinite 
power  and  intelligence.  Always  among  uncultivated  peoples 


84    MODERN  SCIENCE  AND  MATERIALISM 

unexplained  phenomena  are  referred  to  a  deity,  who  survives 
in  the  imagination  until  such  time  as  the  phenomena  can 
be  explained  by  natural  causes.  The  pertinacity  with  which 
men  clung  to  this  conviction  was  a  measure  of  their  inability 
to  conceive  any  alternative.  But  the  mere  inability  to  con- 
ceive an  alternative  does  not  constitute  any  proof  of  a  theory  ; 
in  so  intricate  a  subject  as  this,  it  does  not  even  constitute 
the  least  probability  in  favour  of  that  theory.  We  may  very 
likely  be  compelled  to  say  that  we  do  not  know  how  these 
things  happened.  Nothing  is  more  probable  than  this;  for 
the  more  we  study,  the  more  we  find  how  little  we  really  do 
know  ;  and  very  likely  the  highest  flight  of  human  knowledge 
will  be  attained  in  the  Socratic  doctrine  that  we  know  nothing. 
But  this  confession  of  our  own  ignorance  is  a  product  only  of 
a  deeper  learning.  Among  primitive  peoples  it  is  unknown. 
Their  range  of  inquiry  and  interest  is,  indeed,  small ;  but  all 
the  gaps  in  it  are  filled  by  deities.  They  ask  few  questions, 
but  those  which  they  ask  they  can  always  answer  ;  for  where 
no  natural  cause  can  be  observed  they  confidently  assign  a 
supernatural  cause,  and  the  matter  is  finished  with.  They 
do  not  know  the  meaning  of  ignorance. 

Among  civilized  men,  the  range  of  inquiry  is  far  wider 
than  among  savages.  But  here,  too,  men  are  largely 
unconscious  of  their  own  ignorance.  They  fill  the  gaps  in 
their  knowledge  with  deities  or  with  a  single  deity,  and  to 
nearly  all  questions  of  philosophic  import  they  are  ready 
with  an  answer.  If  they  know  of  a  natural  cause  for  any 
phenomenon,  they  will  adopt  that  for  preference ;  but  if 
they  cannot  think  of  any  natural  cause,  they  refer  the  matter 
without  further  ado  to  a  deity,  as  the  next  best  solution 
of  the  difficulty.  The  theological  modes  of  thought  are 
based  on  the  assumption  that  man  must  know  everything ; 
the  scientific  modes  of  thought  are  based  on  the  assumption 
that  he  knows  nothing.  Here  and  there  a  problem  can  be 
answered,  but  that  is  an  exception  to  the  rule.  As  our 
range  of  inquiry  widens  out,  the  number  of  insoluble 


LIFE  AND  CONSCIOUSNESS  85 

problems  so  increases  that  it  becomes  an  exception  of  the 
rarest  character.  The  more  we  learn,  the  more  are  we 
oppressed  by  the  portentous  magnitude  of  our  own  ignorance. 
Those  who  like  to  fill  the  gaps  in  their  knowledge  with  a 
deity  may  do  so ;  but  they  must  be  prepared  for  the  chance 
that  those  gaps  may  be  filled  in  time  by  explanations  of  a 
natural  and  not  a  supernatural  character,  so  that  their 
deity  is  driven  homeless  to  some  other  sphere  of  activity. 
This  perpetual  ousting  of  divinities  from  spheres  supposed 
to  be  their  own  is  one  of  the  most  interesting  lessons  of  all 
history,  and  is  largely  responsible  for  the  discredit  into 
which  theological  opinions  have  now  fallen. 

At  all  events,  the  doctrine  of  special  creation  of  species 
was  upset  last  century  by  Darwin's  theory  of  Natural 
Selection.  This  theory  is  based  upon  the  three  pillars  of 
heredity,  variation,  and  the  struggle  for  existence.  Darwin 
assumed  that  a  species  tends  to  vary  equally  in  any  direction. 
Some  variations,  however,  were  favourable  to  the  life  of  the 
individual,  while  others  were  unfavourable  or  indifferent. 
He  assumed,  furthermore,  a  severe  "  struggle  for  existence " 
within  every  species,  as  the  result  of  which  a  large  proportion 
of  each  generation  dies  a  premature  death.  In  this  com- 
petition for  existence,  individuals  who  happen  to  have 
variations  of  a  favourable  character  will  have  an  advantage 
over  the  others,  and  will  be  more  likely  on  the  average  to 
reach  the  age  of  reproduction.  The  succeeding  generations 
will,  therefore,  tend  more  and  more  to  be  recruited  from 
those  who  possess  variations  of  a  life- conserving  utility.  By 
heredity,  these  variations  will  be  handed  down,  and  after 
a  time  will  become  a  general  characteristic  of  the  whole 
species.  This  is  the  theory  of  Natural  Selection,  or,  in 
Spencerian  language,  the  survival  of  the  fittest. 

It  obviously  depends  largely  on  the  rigour  of  the  struggle 
for  existence.  An  example  may  therefore  be  taken,  to  show 
how  extraordinarily  keen  the  process  is.  The  common 
housefly  is  said  to  lay  eggs  in  batches  of  120  to  150  at  a  time, 


86    MODERN  SCIENCE  AND  MATERIALISM 

and  may  deposit  five  or  six  batches  during  its  life.  In  very 
hot  weather  a  generation  extends  to  about  three  weeks ; 
that  is  to  say,  a  newly-laid  egg  develops  into  a  fly,  which  in 
its  turn  is  laying  eggs  within  a  period  of  three  weeks.  Now 
if  we  suppose  that  every  egg  laid  develops  into  a  perfect 
fly,  that  half  the  total  numbers  of  flies  are  females,  that 
every  female  fly  lays  the  normal  number  of  eggs,  and  that 
there  are  six  generations  of  flies  in  a  summer,  a  simple 
calculation  shows  that  at  the  end  of  the  summer  the  progeny 
of  a  single  pair  of  houseflies  reaches  such  an  enormous 
figure  that  if  they  were  all  to  be  pressed  together  into  a 
solid  mass  they  would  occupy  a  space  of  something  like 
a  quarter  of  a  million  cubic  feet,  assuming  200,000  flies  to 
the  cubic  foot.  But  there  is  no  reason  to  think  that  the 
number  of  houseflies  is  on  the  increase.  It  hence  follows 
that  out  of  these  myriads  of  potential  insects,  there  will,  on 
the  average,  be  only  two  individuals  who  survive  to  the 
beginning  of  the  next  breeding  season.  All  the  rest  that 
are  born  die  an  "unnatural"  death.  'Darwin's  theory 
supposes  that  fortunate  variations  of  a  life-conserving 
character  will  be  a  factor  in  the  determination  as  to  which 
two  individuals  out  of  that  whole  immense  multitude  shall 
be  the  survivors.  It  is,  however,  not  very  easy  to  acquire 
complete  conviction  upon  this  point.  The  struggle  for 
existence  is  so  intense  that  nearly  every  potential  individual 
is  overcome  by  it.  The  individual  insect  is  no  match  for  its 
environment ;  the  odds  against  it  are  too  overwhelming. 
Can  it  be  supposed  that  a  small  variation  (for  Darwin 
assumed  that  variations  were  small)  would  make  a  life-and- 
death  difference  in  this  desperate  and  one-sided  struggle? 
The  process  would  be  easier  to  imagine  if  we  assumed,  with 
later  biologists,  that  heritable  variations  of  a  larger  type,  - 
otherwise  called  mutations,  were  the  material  upon  which 
Natural  Selection  worked.  Even  so,  the  practical  working 
of  the  process  is  none  too  easy  to  imagine.  Let  us  pass  on, 
therefore,  to  a  further  illustration. 


LIFE  AND  CONSCIOUSNESS  87 

In  the  minute  water  animals  called  copepods,  the  males 
have  their  anterior  antennae  modified  into  long,  whip-like 
structures  which  they  use  as  a  lasso  to  throw  over  the  heads 
of  the  females,  and  so  to  catch  them  as  they  take  flight. 
The  advantage  of  this  structure  for  securing  survival  is 
obvious.  Those  males  which  were  most  adept  in  catching 
females  would  give  rise  to  a  large  progeny,  inheriting  the 
peculiarity  of  their  parent,  while  the  males  who  had  no 
contrivance  of  this  nature  would  have  but  few  offspring, 
and  would  soon  be  swamped  out.  In  this  case,  it  is  easier 
to  understand  how  a  slight  improvement  in  the  antennae, 
which  facilitated  the  task  of  holding  the  female,  would  give 
the  male  an  advantage  in  reproducing  over  males  which 
had  no  such  favourable  variation.  The  small  variations 
might  thus  become  fixed  and  gradually  increased  by 
heredity. 

The  predominant  opinion  at  the  present  time  is  that 
Natural  Selection  offers  no  adequate  account  of  the  process 
of  organic  evolution.  The  complexity  of  life  is  so  astonish- 
ing and  inconceivable,  the  adjustments  and  interrelations 
both  of  structure  and  function  are  so  infinitely  delicate  and 
elaborate,  that  the  simplicity  and  obviousness  of  Natural 
Selection  appear  altogether  incongruous  by  the  side  of  the 
facts  which  it  is  alleged  to  account  for.  And  there  are 
many  other  difficulties.  Natural  Selection  postulates  that 
every  organic  structure  has  some  life- conserving  value  to 
the  organism.  But  the  number  of  differentiated  parts  of 
a  mammal,  for  instance,  is  so  immense,  that  if  we  suppose 
each  of  them  separately  to  be  developed  by  Natural  Selection, 
the  time  required  for  evolution  would  be  far  greater  than 
is  geologically  possible.  Moreover,  every  structure  in  an 
-organism  is  not  of  life-conserving  value.  Take,  for  instance, 
two  closely  resembling  birds,  the  blackcap  and  the  garden- 
warbler,  both  belonging  to  the  same  genus  Sylvia.  In  every 
respect  of  structure  and  habit,  they  are  exceedingly  alike ; 
even  their  song  is  hard  to  discriminate.  But  one  has  a 


88    MODERN  SCIENCE  AND  MATERIALISM 

black  crown  on  his  head,  and  the  other  has  not.  Now,  if 
Natural  Selection  is  all-embracing,  we  must  suppose  that 
this  black  crown  has  a  survival  value;  and  to  such  an 
extent  that  all  individuals  without  it  have  become  extinct. 

'  That  is  the  extreme  doctrine  of  Natural  Selection.  But  if 
a  black  crown  is  so  vital  a  necessity  to  the  blackcap,  how 
is  it  that  the  gardeu^w^b^r  continues  to  flourish,  though 
his  head  is  of  the  same  dull  colour  as  the  rest  of  his  body  ? 
Must  we  suppose  that  there  is  some  other  obscure  adapta- 
tion, which  relieves  him  from  any  necessity  for  a  black 
head  ?  It  may  be  so ;  but  there  is  not  the  least  ground 
for  thinking  it,  except  for  the  one  purpose  of  maintaining 
the  Darwinian  doctrine.  Moreover,  why  does  the  female 
blackcap  have  a  reddish  instead  of  a  black  crown  ?  They 
each  take  a  turn  at  incubation,  so  that  it  appears  to  be 
of  little  importance  to  the  individual  what  colour  the  crown 
of  his  head  is.  In  short,  the  example  does  not,  indeed, 
disprove  Natural  Selection,  but  it  involves  some  stretching 
of  facts  beyond  what  we  can  observe  in  them.  And  so  in 
multitudinous  other  instances,  facts  have  to  be  stretched  if 
the  theory  is  to  be  maintained,  until  at  last  the  theory 
itself  falls  into  very  grave  doubt.  Finally,  Jacques  Loeb 
has  indicated  sundry  properties  of  animals  which  can  have 
no  utility  to  the  organism  whatsoever. 

To  account  for  these  discrepancies,  various  modifications 
have  been  suggested.  A  structure  may  now  have  no  value 
to  the  individual ;  it  may  be  a  mere  survival  of  a  structure 
which  once  had  a  value,  and  has  now  lost  its  purpose,  and 

•  is  on  the  way  to  extinction  —  as,  for  instance,  the_ judiz 
mentary  legs  of  whales  and  of  snakes,  the  eyes  of  cave- 
dwelling  crustaceans,  and  so  on.  Or  a  structure  may  neither 
at  the  present  nor  at  any  past  time  have  had  any  value,  but 
it  may  be  correlated  in  some  necessary  manner  with  another 
structure  which  has,  or  has  had,  a  value.  But  we  are  here 
already  departing  from  the  all-sufficiency  of  Natural  Selection* 
And  as  we  do  not  see  any  reason  for  supposing  such  correla- 


LIFE  AND   CONSCIOUSNESS  89 

tion,  except  out  of  regard  for  maintaining  the  theory,  it 
remains  a  pure  hypothesis.  It  may  quite  well  be  so,  and 
is  quite  in  accordance  with  what  might  be  expected ;  but 
there  is  no  evidence  of  detailed  cases,  and  so  we  cannot 
say  whether  it  is  so  or  not.  The  more  closely  we  study 
Natural  Selection,  the  more  numerous  are  the  untested  hypo- 
theses which  we  have  to  invoke,  until  at  last  this  clinging 
burden  of  parasitic  hypotheses  threatens  to  submerge  the 
central  doctrine  which  they  were  intended  to  buttress. 

In  short,  the  great  and  enduring  value  of  the  doctrine 
of  Natural  Selection  has  been  somewhat  clouded  by  the 
exaggeration  of  the  claims  made  on  its  behalf.  In  the 
middle  of  last  century,  it  was  a  popular  belief  that  all 
parts  of  an  organism  had  some  utility.  Darwin  accepted 
this  assumption  without  inquiry,  and  on  that  basis  erected 
his  theory.  The  theory  departed  in  many  respects  from 
popular  opinion ;  in  those  respects  it  was  fiercely  assailed, 
and,  as  we  all  know,  it  made  good.  For  it  was  not  in  error 
where  it  differed  from  popular  opinion ;  it  was  in  error 
only  where  it  agreed  with  popular  opinion,  and  thus 
escaped  criticism.  Popular  opinion  was  wrong  from  top  to 
bottom ;  Natural  Selection  was  a  first  approximation  to  the 
truth,  but  it  was  unfortunately  hailed  as  the  whole  truth 
by  its  disciples,  and  attacked  on  mythological  grounds  by 
its  adversaries,  a  mode  of  attack  which  ultimately  tended  to 
strengthen  rather  than  weaken  it. 

Natural  Selection,  then,  is  a  plausible,  even  if  it  is  not 
the  sole  factor  in  the  development  of  utilitarian  structures. 
The  real  value  of  the  theory  is  not  in  furnishing  a  cause 
of  evolution,  but  in  showing  why  animals  and  plants  are 
so  largely  purposive  in  their  structure.  Natural  Selection 
shows  that  they  could  not  be  otherwise  than  purposive.  It 
is  clear  that,  on  the  likely  assumption  that  variation  is 
completely  haphazard,  all  variations  that  are  definitely 
unfavourable  will  tend  to  die  out,  for  the  simple  reason 
that  the  organism  possessing  them  cannot  exist.  Neutral 


90    MODERN  SCIENCE  AND  MATERIALISM 

variations  will  tend  in  a  lesser  degree  to  disappear.  For  the 
possession  of  a  useless  organ  will  necessarily  constitute  a 
handicap  in  the  struggle  for  existence ;  it  draws  sustenance, 
has  to  be  carried  about,  is  a  burden  on  the  organism,  to 
which  it  gives  no  counterbalancing  advantage.  Often, 
indeed,  like  the  crown  of  the  blackcap,  it  entails  no  extra 
demand  upon  the  animal ;  and  in  all  cases  of  that  kind, 
1  Natural  Selection  is  inoperative.  Thus,  Natural  Selection 
shows  us  why  animals  and  plants  on  the  whole  are  organized 
on  a  purposive  basis.  If  they  were  not,  they  could  never 
»  have  evolved.  Natural  Selection  is  not  a  cause  of  evolution, 
'but  a  condition  of  evolution.  It  limits  evolution  in  the 
main  to  what  we  call  purposive  effects.  It  rules  out  all 
other  possible  spheres  of  development,  leaving  only  this  one, 
within  which  all  organisms  have  to  evolve,  unless  they  die 
out.  It  has  an  added  philosophic  interest,  in  showing  how 
a  teleological  organization  may  be  achieved  by  blind  physical 
laws.  Animals  and  plants  are  teleologically  organized, 
because  they  cannot  be  anything  else. 

The  real  causes  of  evolution  are  no  more  known  than  the 
causes  of  variation.  Various  factors  have  been  at  one  time 
or  other  suggested  ;  in  particular  it  used  to  be  believed  that 
somatic  modifications  could  be  inherited,  and  that  the 
environment,  acting  direct  upon  the  soma,  could  modify 
the  germ-plasm.  But  this  belief  has  now  been  generally 
abandoned,  and  the  position  is  that  very  little  is  known 
as  to  the  causes  of  evolution.  We  have  for  the  present 
to  be  content  with  the  fact. 

The  question  has  been  widely  discussed  how  life 
originally  started  upon  the  Earth.  One  of  the  most 
popular  theories  is  that  living  germs  were  brought  to  the 
Earth's  surface  by  meteorites,  which  are  constantly  falling 
upon  our  globe.  Many  difficulties  confront  this  theory ; 
and  Arrhenius  suggested  a  modification,  according  to  which 
the  germs  were  driven  through  space  by  the  radiation 
pressure  of  light,  and  not  on  any  material  body.  Their 


LIFE  AND  CONSCIOUSNESS  91 

infinitesimal  size  would  justify  the  belief  that  they  may  be 
conveyed  along  on  the  phantom  wings  of  a  wave  of  light. 

No  explanation  of  this  character  is  satisfactory,  however. 
It  is,  of  course,  purely  a  guess,  but  then  speculations  on  the 
origin  of  life  can  scarcely  be  more.  Even  as  a  guess,  it  is 
far  from  satisfying ;  for  it  offers  no  solution  of  the  origin  of 
life,  but  only  of  the  way  in  which  life  got  on  to  the  Earth. 
It  merely  removes  the  difficulty  one  step  out  of  sight ;  it 
transfers  the  problem  from  the  Earth  to  another  and 
unknown  part  of  the  Universe.  Let  us  look  at  the  matter 
broadly. 

The  integrated  bodies  which  are  suspended  at  vast 
intervals  throughout  our  Universe — bodies  which  we  call 
planets  and  suns — are  believed  to  have  been  derived  in 
the  course  of  unimaginable  epochs  of  time  from  nebulas. 
As  to  how  the  evolution  proceeds,  the  physical  causes  at 
work,  there  has  been  wide  speculation ;  but  we  are  now 
concerned  only  with  the  end-product,  the  appearance  of 
bodies  at  enormously  high  temperatures,  which  gradually 
fall  to  the  cold  of  surrounding  space.  It  is  not  known  what 
temperature  exists  in  the  hottest  stars ;  30,000°  C. 
(54,000°  F.)  has  been  suggested,  on  which  basis  the  Sun 
now  would  be  over  8000°  C.  (say,  15,000°  F.)  But  this  is  a 
mere  guess.  It  indicates,  however,  the  enormous  difference 
of  physical  conditions  prevailing  at  the  outset  of  evolution, 
by  comparison  with  conditions  now  prevalent  on  the  Earth. 
In  these  very  hot  stars,  there  is  every  reason  to  believe  that 
matter  exists  in  a  very  different  form  from  that  in  which  we 
know  it.  The  spectroscope  discloses  in  them  very  few  of 
the  elements  which  we  know  on  the  Earth,  and  those 
few  for  the  most  part  of  the  simpler  and  lighter  kinds. 
Even  these  elements  appear  often  to  exist  in  embryonic 
forms  only,  to  which  have  been  given  the  names  proto- 
hydrogen,  proto-iron,  etc.  We  cannot  doubt  that  they  are 
ultimately  composed  of  electrons ;  but  we  have  no  reason  to 
think  that  the  electrons  are  combined  together  to  form 


92    MODERN  SCIENCE  AND  MATERIALISM 

just  the  atoms  we  now  know,  and  no  others.  The  original 
primeval  atoms  of  an  early  star  are  something  more 
rudimentary  than  the  simplest  of  all  our  atoms — that  of 
hydrogen.  Nor  are  we  obliged  to  assume  that  the  matter 
of  which  they  were  composed  must  exist  in  one  of  the  three 
states — solid,  liquid,  or  gas.  Just  as  the  atoms  differ  from 
our  atoms,  so  the  matter  which  they  form  may  exist  in  some 
fourth  state,  of  which  we  have  no  experience. 

As  evolution  advances,  and  the  stars  get  cooler,  a  greater 
number  and  variety  of  atoms  appear  on  them.  Iron  and  the 
metals  are  formed,  and  the  number  of  substances  gradually 
increases,  until,  at  temperatures  corresponding  to  our  own, 
we  find  a  wealth  and  complexity  of  different  substances 
resembling  those  which  we  know.  In  short,  a  spectroscopic 
study  of  the  stars  indicates  that  the  most  elementary  atoms 
are  formed  first ;  then  the  heavier  ones ;  and  lastly  the 
heaviest  of  all,  uranium,  thorium,  radium,  which,  as  conditions 
continue  changing,  begin  to  disintegrate  again  as  they  are  now 
doing  upon  the  Earth.  In  short,  a  true  natural  selection 
occurs  in  the  atomic,  as  in  the  organic  world.  Atoms  of 
any  kind  may  be  formed,  but  only  certain  kinds  are  suited  to 
their  environment,  and  they  alone  persist.  At  one  period 
the  environment  favours  the  existence  of  certain  new  atoms ; 
but  at  a  later  period  does  not  favour  their  existence,  so  that 
they  tend  to  extinction.  Uranium  on  the  Earth  is  travel- 
ling the  same  path  that  Dinosaurs  have  already  travelled, 
and  very  broadly  for  the  same  reasons  of  philosophical 
physics.  If  we  were  made  of  uranium,  instead  of  proto- 
plasm, we  should  apply  the  term  "  purposive "  not  to  the 
reactions  of  organic  matter,  but  to  the  chemical  properties 
of  uranium. 

After  a  certain  period  of  evolution,  a  stage  is  reached  like 
that  of  our  Sun,  a  monstrous  maelstrom  of  wildly  agitated 
matter  and  energy,  with  a  heat  that  burns  and  a  light  that 
dazzles  a  hundred  million  miles  away — while  from  its  surface 
there  spring  forth  from  time  to  time  great  jets  of  gas,  which 


LIFE  AND  CONSCIOUSNESS  93 

in   ten   seconds   may   reach   the  height   of  300,000   miles. 
Plainly  no  life  is  possible  there. 

Let  us  transfer  our  attention  now  to  the  Earth.  As 
cooling  proceeds,  an  external  crust  begins  to  appear,  a 
differentiation  between  the  inside  and  the  outside.  At  first 
it  is  thin,  rocking  upon  the  oceans  of  gas  beneath,  and  is 
often  broken  through.  Dense  clouds  of  vapour  obscure  the 
Sun ;  titanic  hurricanes  shake  the  very  surface  of  the  Earth, 
while  deluges  of  hot  and  acid  rain  gradually  pile  up  the 
waters  of  the  ocean.  Later  still,  the  crust  becomes  more 
stable.  During  the  molten  stage  the  heavier  substances,  like 
metals,  had  largely  sunk  within  ;  the  lighter — the  quartz  and 
the  feldspar — now  freeze  upon  the  surface,  leaving  a  bald 
expanse  of  granite  over  which  the  waters  continue  to 
accumulate. 

Now  is  the  time  when  we  must  look  for  the  origin  of  life. 
The  atmosphere  has  discharged  the  greater  part  of  its  water- 
vapour;  the  clouds  at  length  break,  and  the  Sun  shines 
for  the  first  time  upon  the  newly-formed  crust  of  the  Earth. 
The  temperature  of  that  crust  has  fallen  well  below  the 
boiling-point  of  water.  The  conditions  have  arisen  in  which 
yet  a  new  substance  can  be  synthetized — the  substance  which 
we  call  protoplasm.  Why  need  we  look  to  distant  corners 
of  the  Universe  for  the  origin  of  life  ?  We  know  that  the 
conditions,  wherever  it  originated,  must  have  been  something 
like  those  existing  on  the  Earth.  What  need  then  is  there  of 
extraneous  hypotheses  and  an  exotic  origin  ?  We  know  that 
the  Earth  was  suitable  for  life ;  we  have  no  observational 
evidence  that  any  other  part  of  the  Universe  was  suitable. 
We  have  to  assume,  firstly,  that  some  other  part  of  the 
Universe  was  suitable,  and  secondly,  that  the  germs  could  be 
conveyed  across  space.  Why  then  drag  in  these  two  hypo- 
theses, with  their  attendant  difficulties,  when  they  add  not  a 
whit  to  our  comprehension  of  the  matter  ?  For  it  is  in  every 
way  simpler  and  requires  far  fewer  assumptions  to  suppose, 
that  the  life  of  the  Earth  originated  on  the  Earth.  This 


94    MODERN  SCIENCE  AND  MATERIALISM 

assumption  is  just  as  easy  to  conceive  as  that  it  originated 
elsewhere,  and  is  not  beset  by  the  further  almost  insuperable 
difficulties  as  to  how  it  traversed  space. 

The  real  reason  why  life  is  imagined  to  have  been  intro- 
duced on  to  the  Earth  is  to  get  over  the  difficulty  of  its 
origin  by  assuming  that  it  always  has  existed  somewhere  since 
the  beginning  of  time.  Now  life  is  merely  a  name  for  the 
sum-total  of  the  physico-chemical  properties  of  protoplasm. 
Why  are  we  to  suppose  that  protoplasm — the  most  unstable 
and  perishable  of  substances — has  existed  through  all  eternity  ? 
Other  far  simpler  substances  are  integrated  and  disintegrated 
as  their  environment  changes.  Has  protoplasm  alone  survived 
all  the  incidents  of  cosmic  evolution  ?  A  fortiori  the  simpler 
inorganic  substances  have  done  the  same,  then ;  and  the 
Universe  a  myriad  aeons  ago  was  not  so  different  from  the 
Universe  of  to-day.  If  there  were  a  vital  principle,  an  essence 
of  life,  then,  indeed,  it  might  survive  for  ever,  for  anything 
might  be  predicated  of  it.  But  if  life  is  a  mere  manifestation 
of  protoplasm,  the  doctrine  of  its  permanency  loses  all 
verisimilitude. 

It  is  undoubtedly  true  that  no  reliable  evidence  exists  to 
indicate  that  at  the  present  time  life  is  being  evolved  de  novo 
from  inorganic  substances.  In  fact  it  is  very  nearly  certain 
that  no  origination  of  life  on  the  Earth  is  now  taking  place, 
at  least  in  a  form  that  can  be  detected  under  the  microscope. 
This  truth,  however,  has  no  bearing  on  the  question  whether 
life  originated  under  the  altogether  different  conditions  of  the 
Earth's  surface  at  the  period  to  which  we  are  alluding.  In 
any  case,  since  there  is  no  fragment  of  evidence  upon  the 
matter,  there  is  no  question  at  all  that  the  simplest  and  most 
probable  hypothesis  we  can  form  is  that  the  formation  of 
organic  substances  follows  the  same  principle  as  the  formation 
of  inorganic  substances.  In  the  earliest  phase  of  stellar 
evolution,  the  substances  in  existence  are  few  and  elementary ; 
at  later  stages  they  become  gradually  more  numerous  and 
more  complex  ;  until  at  last  synthesis  of  the  carbon  compounds 


LIFE  AND   CONSCIOUSNESS  95 

gives  rise  to  the  proteins,  more  varied  and  more  complex 
than  any  substances  previously  formed.  If  it  were  not  for 
the  mythological  bias,  no  one  would  ever  have  suggested  that 
the  highly  complex  compounds  of  carbon  were  formed  in  any 
different  way  from  the  compounds  of  any  other  element. 

Whenever  it  was  that  the  Earth's  surface  was  first 
able  to  support  life,  it  seems  reasonable  to  believe  that  the 
rudimentary  proto-organisms  were  considerably  simpler  than 
the  simplest  we  can  now  see.  The  very  elementary  amoeba, 
one  of  the  simplest  of  all  animals,  has  already  a  definite 
structure  and  stable  physiology.  It  has  a  nucleus,  a  con- 
tractile vacnole,  its  exterior  and  interior  are  differentiated ; 
the  functions  of  nutrition  and  excretion  are  elaborate  and 
definitely  specific.  The  amoeba  has  already  travelled  a  long 
way  from  its  ancestral  inorganic  parentage :  it  must  be  the 
product  of  a  long  evolution,  the  earlier  phases  of  which  are 
now  either  extinct  or  unrecognizable  through  the  microscope. 
The  origin  of  life,  we  may  reasonably  suppose,  was  as  primitive 
specks  of  protoplasm,  of  exceeding  minuteness,  and  showing 
scarcely  a  trace  of  any  structural  differentiation  ;  and  probably 
ages  must  have  elapsed  before  any  creature  of  so  specialized 
a  character  or  so  large  a  size  as  amoeba  could  be  developed. 
Indeed,  if  life  is  still  originating  de  novo  on  the  Earth,  it 
would  be  too  much  to  expect  that  our  microscopes  could 
discover  it. 

Once  the  germs  of  life  were  in  existence,  the  great  differen- 
tiation soon  began  between  animal  and  plant  life.  Whether 
these  are  the  only  possible  forms  of  life,  or  whether  on  other 
planets  or  in  other  parts  of  the  Universe  quite  different  forms 
of  life  may  have  been  evolved,  we  cannot  tell.  We  may  be 
certain,  indeed,  that  their  species  are  intensely  different  from 
ours.  At  all  events,  we  know  that  on  this  particular  planet 
two  main  forms  of  life  appeared,  which  we  call  animal  and 
plant.  The  records  of  their  evolution  are  preserved  to  us  in 
the  form  of  fossils.  These  records  begin  somewhat  late  :  not 
until  the  habit  of  secreting  lime  resulted  in  hard  skeletons 


96    MODERN  SCIENCE  AND  MATERIALISM 

which  could  endure  through  geologic  epochs.  By  that  time, 
the  main  invertebrate  groups  had  already  come  into  existence  ; 
the  story  of  their  evolution  is  thus  lost  in  the  hopeless 
mystery  of  a  past  that  is  enormously  remote.  The  vertebrates, 
on  the  other  hand,  were  just  beginning  their  career.  The 
theory  now  most  generally  accepted  is  that  vertebrates  took 
their  origin,  not  in  the  sea,  but  in  the  running  waters  of  the 
land.  In  any  case,  they  breathed  by  means  of  gills,  and  the 
change  from  a  water  to  a  land  life  must  have  been  a  formidable 
crisis  of  their  development.  It  was  perhaps  due  to  a  period 
of  great  aridity,  which  gave  a  powerful  impetus  to  the 
evolution  of  such  creatures  as  could  live  apart  from  water. 
The  earliest  known  fishes  with  lungs  belong  to  the  period  of 
the  Lower  Devonian.  How  precisely  they  emerged  from  the 
water  to  live  upon  the  land  is  a  subject  only  of  speculation. 
But  the  fact  remains  that  they  lost  their  gills,  grew  lungs, 
took  to  breathing  air,  and  to  walking  upon  the  dry  land. 

Up  to  this  period  no  trace  of  any  land  vertebrates  have 
been  found.  But  at  length,  on  reaching  the  rocks  of  the 
Upper  Devonian,  the  footprint  of  a  land  vertebrate  has  been 
discovered.  This,  the  earliest  known  terrestrial  footprint, 
indicates  an  animal  with  at  least  four  toes,  the  first  and  the 
second  being  by  far  the  largest.  These  amphibians  soon 
began  to  abound  when  a  wetter  age  succeeded.  Swamps, 
jungles,  and  forests  were  then  their  habitat — those  same 
forests  which  at  distant  future  ages  were  destined  to  supply 
us  with  coal.  They  had  a  protective  covering  of  armour, 
looking  like  immense  but  stumpy  newts.  They  had  not  yet 
lost  all  connection  with  their  ancient  home  in  the  water,  for 
they  still  went  there  to  breed  and  their  young  were  still  born 
with  gills. 

A  new  age  of  drought  came  on,  however ;  the  rivers  began 
to  dry  up,  and  the  amphibians  found  it  increasingly  difficult 
to  obtain  sufficient  water  for  their  breeding  purposes.  Under 
these  circumstances,  they  gradually  abandoned  the  water  and 
took  altogether  to  the  land ;  and  thus  perhaps  were  reptiles 


LIFE  AND  CONSCIOUSNESS  97 

formed.  The  reptiles  divided  into  two  main  branches,  one  of 
which  led  to  Dinosaurs  and  to  birds ;  the  other  to  mammals, 
and  ultimately  to  Man.  Owing  possibly  to  a  severe  glacial 
epoch  in  early  Permian  time,  both  branches l  acquired  warm 
blood,  which  protected  them  from  the  extreme  rigours  of  the 
age.  But  at  first  the  mammals  showed  no  signs  of  their  future 
greatness ;  they  were  small  and  humble  creatures,  which  fled 
precipitately  on  the  approach  of  the  carnivorous  reptiles. 
Throughout  the  vast  era  of  Mesozoic  time,  Dinosaurs  (mostly 
not  carnivorous)  were  monarchs  of  the  Earth.  Of  immense 
size  and  high  specialization,  they  entirely  dominated  the  land 
surface  of  the  Earth ;  and  we  can  well  imagine  our  small 
mammalian  ancestors  scuttling  away  at  their  approach  into 
the  nearest  thicket  of  ferns  or  cycads.  Had  some  denizen  of 
another  planet  visited  our  Earth  during  this  period,  and  had 
he  been  addicted  to  teleological  explanations,  it  would  have 
been  obvious  to  him  that  the  great  Dinosaurs,  walking  on 
their  two  hind-legs,  were  the  lords  of  creation.  He  would 
have  noticed  that  it  was  an  age  of  reptiles,  for  whose 
sustenance  an  all-wise  Creator  had  supplied  a  number  of 
small  hairy  creatures,  running  timidly  on  all-fours,  but  not 
too  difficult  to  catch.  He  would  scarcely  credit  the  hypothesis 
of  "  civilized  "  man,  that  the  Earth,  the  reptiles  and  all  other 
forms  of  life,  nay,  even  the  sun,  moon  and  stars,  were  really 
made  in  the  interests,  and  for  the  exclusive  purposes  of, 
certain  among  those  furry  quadrupeds  who  happen  to  be  the 
ancestors  of  Man. 

At  all  events,  after  many  million  years  the  Mesozoic  period 
passed  away ;  the  reptiles  declined  from  their  former  great- 
ness, and  left  the  ground  comparatively  free  for  the  rise  of  the 
age  of  mammals.  How  the  Reptile  Cynodonts  developed  into 
mammals  is  not  known  ;  but  after  the  evolution  had  taken 
place,  there  occurred  the  long  stagnation  already  mentioned, 
under  the  heel  of  the  reptiles.  The  first  age  of  "archaic" 
mammals  was  swept  away  by  an  invasion  of  more  modernized 

1  Possibly  not  the  Dinosaurs. 
H 


98    MODERN  SCIENCE  AND  MATERIALISM 

mammals  during  the  period  of  the  Eocene.  These,  and 
further  waves  of  invasion,  appear  to  have  emanated  from 
Northern  Asia,  or  at  least  from  circumpolar  regions.  Thence 
they  spread  South,  and  after  one  or  two  waves  which  brought 
monkeys  on  their  crest,  one  came  at  last  which  brought 
men.  Their  evolution  from  an  arboreal  ape,  like  the  gibbon, 
may  perhaps  have  taken  place  in  Central  Asia.  In  any  case, 
it  seems  to  be  geologically  a  very  recent  event,  dating  back 
to  the  inception  of  the  last  Glacial  epoch,  which  may,  perhaps, 
have  occurred  something  like  100,000  years  ago.  It  is  futile 
to  give  figures  as  to  the  age  of  the  Earth  or  the  different 
geologic  periods,  for  no  approach  to  real  knowledge  has  yet 
been  attained.  Still,  guesses  may  be  useful  in  order  to  get 
a  general  idea  of  the  proportion  of  the  various  events,  so  long 
as  we  avoid  regarding  the  hypothetical  figures  as  any  real 
index  to  the  facts.  On  this  basis,  we  might  set  the  age  of 
the  Earth  geologically  at  1000  million  years.  In  that  case, 
the  Age  of  Reptiles  might  have  begun  about  200  million  years 
ago,  and  lasted  over  100  million  years.  Supposing  that  the 
dominance  of  mammals  began  fifty  million  years  ago,  the 
result  emerges  that  however  inaccurate  our  figures  may  be, 
one  thing  is  certain,  the  evolution  of  man  from  the  apes  is 
an  occurrence  of  extraordinary  recency. 

At  length  the  records  of  geology  give  place  to  those  of 
archaeology.  Eoliths  are  found — curiously  shaped  pieces  of 
flint  which  may  or  may  not  be  of  human  workmanship. 
Then  comes  the  Palaeolithic  or  Early  Stone  Age,  with  flint 
implements,  roughly  shaped,  but  of  undeniable  human  orgin. 
At  this  time  the  face  of  Europe  was  still  very  different  from 
what  it  is  at  present.  Great  Britain  was  united  to  the 
continent  along  its  eastern  and  southern  boundaries.  Where 
the  North  Sea  now  is,  was  a  wide  valley,  down  which  flowed 
the  waters  of  the  Rhine,  swelled  by  its  tributary,  the  Thames, 
and  reaching  the  sea  not  far  from  the  Faroe  Islands.  Where 
the  English  Channel  now  is,  was  similarly  the  valley  through 
which  the  Seine  reached  its  destination  in  the  Atlantic  Ocean. 


LIFE  AND  CONSCIOUSNESS  99 

The  Mediterranean  was  traversed  by  an  isthmus  connecting 
Africa  through  Sicily  with  Europe.  Possibly,  Europe  was 
still  connected  with  Greenland  through  Iceland  and  the 
Faroes.  The  Great  Ice  Age  had  completed  its  first  episode ; 
the  ice  which  had  covered  the  greater  part  of  Europe  had 
receded  for  a  time  and  left  a  fine  warm  climate.  In  England, 
elephants  and  rhinoceroses  wandered  at  large.  Hippopo- 
tamuses disported  themselves  in  the  waters  of  the  Thames. 
Bison,  wild  horses,  deer,  and  the  sabre-toothed  tiger  were  all 
common. 

Gradually  the  ice  began  to  advance  again.  The  hippo- 
potamus and  other  denizens  of  a  warm  country  disappeared. 
The  mammoth  became  abundant ;  and  among  other  animals 
were  the  reindeer,  mus'k-ox,  glutton,  arctic  fox,  and  lemming. 
It  was  perhaps  owing  to  the  steady  deterioration  of  the 
weather  that  Man  first  took  to  living  in  caves,  where  he 
made  those  wonderful  paintings  that  are  still  to  be  found. 
At  one  of  these  caves,  at  Niaux  in  the  Pyrenees,  may  still  be 
seen  in  the  sand  the  imprint  of  a  human  foot,  left  there  we 
know  not  how  many  thousand  years  ago.  The  dominant  race 
of  that  age  seems  not  to  have  been  artistic,  however.  Their 
skeletons  suggest  a  race  of  man  who  had  a  very  large  nose 
and  long  upper-lip.  Over  the  eyes  extended  a  prominent 
ridge,  and  the  forehead  was  receding.  The  jaws  were  large 
and  heavy,  especially  the  lower  jaw,  which  was  further 
remarkable  for  the  absence  of  a  chin.  The  wisdom  teeth, 
instead  of  being,  as  among  existing  men,  the  smallest  of  the 
molars,  were  the  largest. 

Some  of  these  ancient  men  appear  to  have  had  brains  even 
larger  than  those  of  modern  Europeans.  And  they  must 
indeed  have  needed  them,  to  protect  themselves  from  the 
terrible  rigours  of  the  Great  Ice  Age.  It  is  not  known  when 
the  discovery  of  fire  was  made,  nor  when  men  began  to 
communicate  their  ideas  by  means  of  language.  But,  at  all 
events,  the  artistic  races  of  Palaeolithic  hunters  were  swept 
away  not  less  than  7000  years  ago  by  the  Neolithic  men,  who 


100    MODERN  SCIENCE  AND  MATERIALISM 

tilled  the  land,  kept  herds,  built  modern  houses,  sometimes 
on  piles  in  the  water,  like  the  Glastonbury  lake-dwellers. 
Their  implements,  though  still  made  either  of  flint  or  green- 
stone, were  often  polished,  and  showed  a  very  high  standard 
of  workmanship.  For  the  Ice  Age  had  finally  passed  away ; 
the  climate  was  mild ;  Europe  was  a  rich,  moist  pasture-land 
with  abundant  peat-bogs  and  woodlands. 

It  was  perhaps  in  North  Africa  that  the  use  of  iron  was 
first  discovered.  Dates  are  still  dubious,  but  it  may  have  been 
6000  years  ago.  And  it  was  then,  or  later  perhaps,  when  the 
big  stones  of  Stonehenge  were  being  set  in  position,  that  the 
Bronze  Age  replaced  the  Stone  Age.  The  Ancient  Britons 
were  still  in  the  Bronze  Age  at  the  time  of  the  Roman 
Conquest.  The  Romans  themselves  had  already  passed  from 
it  to  the  Iron  Age  some  centuries  previously.  And  so,  at 
length,  archaeology  passes  into  history.  The  arts  of  writing 
and  of  numeration  are  invented.  Artistic  genius  suddenly 
bursts  forth  in  the  wonderful  efflorescence  of  Greek  civiliza- 
tion, which  died  down  after  a  brief  life,  almost  as  quickly 
as  it  appeared.  Philosophy  took  shape,  and  advanced  to  a 
surprising  height,  till  it  was  overwhelmed  again  by  a  thousand 
years  of  barbarism  and  religion.  But  the  light  dawned  once 
more  with  modern  history.  Printing  was  invented.  Philo- 
sophy, science,  and  art  slowly  evolved  to  their  present  state. 
In  the  case  of  science,  the  advance  is  cumulative.  The  genius 
of  individuals  does  not  perish,  as  it  does  in  art :  it  becomes  the 
property  of  all  men,  and  each  generation  starts  its  labours  on 
a  higher  platform  than  its  predecessors. 

We  conclude,  then,  that  Life  is  a  name  for  certain  properties 
of  protoplasm,  and  that  biology  is  the  science  which  deals 
with  the  physico-chemical  reactions  of  that  highly  complex 
substance.  We  find,  moreover,  that  protoplasm,  in  common 
with  far  simpler  substances,  undergoes  an  evolution ;  and  the 
fabulously  protean  forms  which  it  adopts  are  the  outward  and 
visible  sign  of  a  fabulous  molecular  complexity  within. 
We  have  dealt  with  Life,  but  we  have  not  yet  dealt  with 


LIFE  AND  CONSCIOUSNESS  1O1 

consciousness,  seemingly  so  different  in  texture  from  all  other 
classes  of  phenomena.  The  actual  relation  of  mind  to  matter 
will  be  dealt  with  in  later  chapters.  What  we  have  at 
present  to  discuss  is  where  consciousness  first  appears  in  the 
course  of  cosmic  evolution. 

The  most  plausible  belief  is  that  it  is  coeval  but  not  coex- 
tensive with  life.  We  note  about  both  of  them  that  they 
stand  in  closer  relation  to  function  than  they  do  to  structure. 
A  unit  of  protoplasm,  in  which  all  physico-chemical  processes 
are  at  a  complete  standstill  is  no  longer  alive  but  dead. 
Spores  and  seeds,  in  which  no  visible  alteration  is  taking 
place,  are  none  the  less  in  process  of  alteration.  They  may 
be  kept  some  years  without  losing  their  powers  of  growth 
or  germination.  Indeed,  it  used  to  be  asserted  that  seeds 
preserved  with  Egyptian  mummies  are  still  capable  of 
germination,  but  this  is  now  known  to  be  a  myth.  However 
lifeless  a  living  thing  may  seem,  there  are  always  some 
physiological  processes  going  on  while  it  has  life ;  and  if 
seeds  are  kept  from  germination,  they  lose  their  vitality  and 
die  in  quite  a  few  years.  Life  is  signalized  by  incessant 
physiological  change.  It  is  not  structure  but  function  that 
constitutes  life,  and  the  same  truth  holds  of  consciousness. 
They  are  not  things  but  processes,  or  a  congeries  of  processes. 

Life  is  a  name  for  the  physico-chemical  reactions  peculiar 
to  protoplasm,  and  when  those  peculiar  reactions  cease,  life 
is  extinct.  Doubtless  structure  in  all  cases  underlies  function  ; 
and  the  cessation  of  the  reactions  implies  molecular  alteration 
in  the  protoplasm.  Now,  seeing  the  general  resemblance 
between  the  conception  of  life  and  the  conception  of  con- 
sciousness, are  we  not  to  infer  an  essential  similarity  in  their 
origin  ?  Can  we  associate  consciousness  with  the  reactions 
of  any  specific  material  substance,  as  we  associate  life  with 
the  reactions  of  protoplasm  ?  We  most  certainly  can. 
Every  modern  psychologist  agrees  that  consciousness  stands 
in  special  relation  to  the  functions  of  the  nervous  system. 
What  we  call  consciousness  appears  on  the  objective  side 


102    MODERN  SCIENCE  AND  MATERIALISM 

as  the  activity  of  certain*  portions  of  the  brain.  Specific 
physico-chemical  reactions  of  nerve-tissue  are  an  invariable 
aspect  of  all  forms  of  consciousness.  I  propose,  indeed,  to 
show  later  that  these  specific  reactions  actually  are  conscious- 
ness, in  precisely  the  same  way  that  the  specific  reactions  of 
protoplasm  actually  are  life.  In  neither  case  is  there  a 
separate  existence  or  entity ;  though  our  own  outlook  is  so 
intensely  central  and  interested,  as  to  make  the  fundamental 
unity  somewhat  difficult  to  perceive. 

We  must  leave  the  formal  proof  of  this  doctrine  to 
Chapter  VI.  For  the  present  we  note  it  only  for  the 
purpose  of  identifying  the  moment  of  entry  of  consciousness 
into  the  course  of  evolution.  It  appeared  when  nervous 
tissue  first  appeared.  And  since  even  the  elementary  amoeba 
possesses  throughout  its  body  the  rudiments  of  nervous 
function,  we  must  suppose  that  the  rudiments  of  conscious- 
ness date  right  back  to  the  earliest  phases  of  animal  life. 
It  would,  indeed,  be  difficult  to  harbour  any  alternative  hypo- 
thesis. Evolution  presents  an  unbroken  chain  from  pre- 
Protozoan  life  down  to  Man.  Throughout  that  period  the 
germ-plasm  has  retained  its  individual  material  continuity. 
There  has  never  been  a  new  germ-plasm  through  all  those 
ages  of  evolution ;  it  is  the  same  old  individual  germ-plasm 
changing  its  chemical  constitution.  There  is  no  point  of 
evolution  at  which  we  can  conceive  the  entry  of  a  totally  new 
thing.  The  rudiments,  the  potentiality,  of  consciousness 
were  present  from  the  start. 

The  conclusions  of  the  last  two  chapters  may  be  summed 
up  in  a  few  lines.  The  final  and,  as  far  as  we  can  tell, 
unchangeable  units  of  existence  are  the  electrons.  They  are 
not  matter,  they  are  not  energy;  but  from  them  both 
matter  and  energy  are  born.  The  electrons  combine  together 
in  a  number  of  different  ways,  and  we  get  a  corresponding 
variety  of  atoms.  The  atoms  combine,  and  we  get  molecules. 
Some  of  these  molecules  contain  vast  numbers  of  atoms. 
These  complex  entities  combine  again  to  form  the  still  more 


LIFE  AND   CONSCIOUSNESS  103 

inconceivably  elaborate  substances  called  proteins.  And  yet 
again  the  protein  molecules  join  together  in  systems,  till  we 
get  still  another  substance,  protoplasm,  where  the  incredible 
degree  of  chemical  elaboration  has  reached  such  a  state  as  to 
have  lost  all  semblance  to  the  simple  reactions  of  the 
laboratory.  The  sum-total  of  these  reactions  is  so  far 
beyond  the  range  of  chemical  analysis  that  we  can  do  no 
more  than  lump  them  stupidly  together  and  call  them  collec- 
tively by  a  new  name — Life.  Nor  have  we  yet  done.  Further, 
elaboration  of  the  molecules  of  protoplasm  gives  rise  to  a  new 
and  distinctive  set  of  reactions,  which  again  paralyze  the 
intellect  of  Man ;  and  he  can  do  no  more  than  invent  a  name 
for  them — he  calls  them  Consciousness. 

Are  the  marvels  of  Life  and  Consciousness  any  greater  than 
those  disclosed  to  us  by  Astronomy,  or  those  disclosed  by 
Physics  ?  It  is  hard  to  say.  One  thing  alone  is  obvious. 
In  all  these  three  spheres  we  come  at  the  very  first  step  upon 
facts  so  remote  from  common  life  as  to  overwhelm  the  imagina- 
tion with  the  magnitude,  with  the  smallness,  with  the  variety 
of  our  Universe.  Our  faculty  of  wondering  is  quickly 
exhausted  in  all  spheres.  We  can  only  feel  vaguely  that  in 
any  of  them,  no  finite  imagination  would  suffice  to  represent 
the  facts.  To  appreciate  them  in  their  reality,  we  should 
have  to  be  gods  and  far  more  than  gods.  We  are  forced 
to  the  conclusion,  not  merely  that  we  can  have  no  understand- 
ing of  these  things,  but  further,  that  there  can  be  no 
understanding  of  them  anywhere. 


CHAPTER  IV 

THE    FALLACY    OF    VITALISM 

THE  most  acute  phase  of  the  conflict  now  raging  between 
spiritualism  and  materialism  is^that  comprised  within  the 
sphere  of  physiology.  During  last  century  the  main  action 
was  carried  on  within  the  confines  of  zoology  and  botany. 
Materialism  there  became  identified  with  the  theory  of 
evolution,  and  especially  of  the  common  origin  of  Man  with 
the  lower  animals.  The  philosophical  controversy  was  for 
the  time  narrowed  down  to  a  single  important  question  of 
fact — a  question  to  which  an  assured  answer  could  be  given 
within  the  range  of  a  single  science.  Many  of  the  disputants 
in  the  evolution  controversy,  indeed,  did  not  perceive,  though 
they  must  certainly  have  felt,  the  larger  philosophical  impli- 
cations of  their  discussions.  They  did  not  overtly  recognize 
what  few  now  would  call  in  question,  namely,  that  the 
evolutionists  were  the  historical  representatives  of  the  materi- 
alistic mode  of  thought ;  that  evolution  v.  fixity  of  species 
was  the  passing  phase  of  a  controversy  which  has  always 
existed,  and  which  indicates  the  greatest  of  all  cleavages 
between  the  opinions  of  intellectual  men.  That  the  true 
nature  of  the  dichotomy  was  more  clearly  perceived  by  the 
spiritualists  may  be  gathered  from  the  unanimity  with  which 
they  attacked  the  new  theory,  and  labelled  it  with  the  titles 
of  materialism  and  atheism. 

Any  such  narrowing  of  this  great  controversy,  so  that  it 
falls  within  .the  limits  of  a  single  science,  is  an  extremely 
welcome  and  valuable  thing.  A  clear  issue  can  be  at  once 
joined  on  a  question  of  fact;  the  question  of  fact  can  be 
decided  by  a  body  of  scientific  investigators,  whose  interest 

104 


THE  FALLACY  OF  VITALISM  105 

is  confined  to  this  point  alone,  and  is  commonly  not  extended 
to  the  larger  philosophic  implications  of  their  decision. 
Effectively,  therefore,  the  point  at  issue  is  decided  exclusively 
on  its  own  merits  by  a  group  of  impartial  and  highly- 
trained  observers,  who  sum  up  among  themselves  the  entire 
knowledge  available  to  humanity  on  the  point  at  issue,  and 
who  are  not  liable  to  be  much  affected  by  those  collateral 
issues  which  excite  such  deep  prejudice  among  the  ignorant 
public,  The  biologists  decided  on  the  truth  of  an  evolution 
theory,  and  the  controversy  then  died  out.  Materialism 
emerged  triumphant  from  the  dispute ;  spiritualism  was 
correspondingly  narrowed  and  depressed. 

Within  the  last  few  years  the  great  dispute  of  philosophy 
has  once  again  been  concentrated  on  one  problem,  whose 
solution  lies  within  the  range  of  a  single  science.  The 
science  to  which  I  refer  is  physiology,  and  the  problem  is 
that  of  mex h a,n  i  sm-^-^&alism .  I  am,  of  course,  very  far 
indeed  from  suggesting  that  this  problem  is  new,  for  it  is 
at  least  as  old  as  the  dispute  on  evolution.  Both  problems 
throw  back  roots  for  several  centuries,  and  were  half  discerned 
even  by  ancient  philosophy.  But  their  prominence  in  men's 
minds  has  constantly  been  altering,  according  to  the  temporary 
phases  of  materialistic  progress.  Whereas  last  century  the 
evolution  theory  rose  to  the  highest  point  of  public  interest, 
and  was  then  settled  for  all  time,  so  now  the  discussion  of 
vitalism  has  acquired  an  exceptional  interest,  if  not  for  the 
general  public,  at  least  for  physiologists  and  psychologists ; 
and  the  universal  acceptance  of  the  mechanistic  solution 
cannot  long  be  delayed.  When  once  this  is  achieved,  the 
ultimate  victory  of  materialism  will  be  immensely  accelerated. 

For  the  purposes  of  this  work,  the  only  branch  of  physiology 
requiring  attention  is  the  physiology,  of  the  nervous  system, 
for  it  is  only  in  this  branch  that  any  remnants  of  vitalism 
survive.  There.  jya&  a  time  when  all  the  functions  of-  the 
body  were  set  down  to  supernatural  agency  or  direction. 
Such,  for  instance,  was  the  case  with  the  production  of 


106    MODERN  SCIENCE  AND  MATERIALISM 

animal  heat  up  to  1780,  when  Lavoisier  and  Laplace  showed 
that  it  depended  upon  oxidation.  The  formation  of  animal 
heat  was  thus  proved  to  be  a  purely  physico-chemical  process, 
of  precisely  the  same  character  as  occurs  in  inorganic  nature. 
In  modern  times,  however,  the  truth  of  mechanism  is  only 
questioned  in  respect  of  the  highest  functions  of  the  nervous 
system — those,  namely,  which  regulate  the  thinking  and 
conduct  of  men. 

Mechanism  is  the  theory  which  regards  the  organism  as 
a  highly  complex  machine,  controlled  exclusively  by  physico- 
chemical  laws,  without  any  sort  of  action  or  guidance 
by  any  force  or  power  foreign  to  the  conceptions  of  physics 
and  chemistry.  (Vitalism,  on  the  contrary,  asserts  that  living 
organisms  possess  within  them  some  directive  power  or  force 
of  non-material  nature,  and  therefore  unknown  to  science. 
This  force,  called  the  vital  force,  is  supposed  to  control  some 
or  all  of  the  activities  of  the  organism.  It  removes  the  living 
body  from  the  exclusive  operation  of  physical  forces,  and 
constitutes  it  something  apart  from  all  other  bodies,  and 
inherently  different  from  them  by  its  very  nature.  On  the 
assumption  of  vitalism,  the  living  organism  is  something 
more  than  an  incident  in  the  universal  redistribution  of 
matter  and  motion ;  its  activities  are  in  part  the  product 
of  totally  new  forces,  which  may  be  manifestations  of  a  soul, 
a  mind,  or  other  spiritual  entity.  It  is  part  of  the  purpose 
of  this  book  to  deny  the  existence  of  entities  of  this  char- 
acter. In  the  region  of  physiology,  therefore,  it  is  necessary 
to  show  that  the  activities  supposed  to  be  due  to  these 
entities  are  in  reality  due  to  physico-chemical  factors.  We 
have  to  consider  not  the  alleged  entities  themselves,  but  the 
alleged  forces  which  they  exert  in  the  animal  organism. 

That  there  is  no  creation  or  destruction  of  energy  within 
the  organism  is  now  an  established  fact.  It  is  no  longer 
questioned  that  the  quantity  of  energy  escaping  from  the 
organism,  in  the  various  forms  of  mechanical  work,  heat, 
chemical  products,  etc.,  is  precisely  equal  to  the  quantity  of 


THE  FALLACY  OF  VITALISM  107 

energy  absorbed  into  the  organism,  whether  in  the  form  of 
chemical  energy  in  the  food,  or  as  light,  heat,  etc.1  It  is 
equally  beyond  dispute  that  the  total  quantity  of  matter 
entering  the  organism  is  precisely  balanced  by  the  quantity 
of  matter  leaving  the  organism,  exclusive  of  that  which  may 
have  been  used  for  growth  of  the  organism,  or  lost  by  a 
diminution  of  its  mass.  We  have  then  this  firm  basis  to 
start  from  :  that,  viewed  as  a  whole  and  from  the  outside, 
the  organism  is  wholly  subservient  to  the  fundamental  laws 
of  physics.  Its  output  of  matter  and  energy  is  identical 
with  the  quantities  supplied  to  it ;  it  is  in  so  far  analogous 
to  a  steam-engine,  or  any  other  artefact  machine. 

After  being  reluctantly  driven  to  the  acceptance  of  this 
fact,  vitalists  were  compelled  to  limit  their  theories  of 
spiritual  control  to  some  abnormal  interference  with  the 
usual  course  of  redistribution  within  the  organism,  an 
interference  which,  while  not  affecting  the  quantity  of 
energy,  yet  caused  it  to  evolve  in  directions  opposed  to 
those  determined  by  the  laws  of  physics.  They  assumed 
that  the  "  vital  force "  might  co-operate  with  physical 
forces  within  the  organism  without  affecting  the  energy 
output.  This  hypothesis,  though  destitute  of  any  single 
fact  to  support  it,  is  compatible  with  the  conservation  of 
energy,  and  is,  therefore,  much  superior  to  the  older  forms 
of  the  vitalistic  dogma.  Analysis,  however,  shows  us  that 
it  is  contradictory  to  other  equally  fundamental  physical 
laws. 

A  force  is  a  name  for  the  influence  by  which  any  portion 
of  matter  tends  to  alter  the  direction  of  motion  of  any  other 
portion.  If  the  exact  distribution  of  matter  and  energy  be 
known,  then  all  the  forces  in  operation  are  also  known. 
That  is  to  say,  all  mechanical  forces  are  dependent  for  their 
existence  solely  on  the  immediate  distribution  of  matter  and 
energy;  and  if  this  distribution  at  any  moment  could  be 

1  Rubner,  Die  Ge  etze  des  Energieverbrauchs  bei  der  Ernahrunf,  1902. 
Also  Atwater,  Reports  of  British  Association,  1904.  ^ 


108    MODERN  SCIENCE  AND  MATERIALISM 

exactly  defined,  all  the  forces  in  operation  at  that  moment 
would  also  be  given.  The  appearance  of  some  new  force, 
not  involved  in  the  given  distribution,  would  imply  the 
appearance  of  new  matter  or  of  new  energy,  or  the  destruc- 
tion of  old  matter  or  energy.  If,  therefore,  the  doctrine  of 
the  vital  force  be  rendered  compatible  with  the  conservation 
of  energy,  it  is  only  by  a  tacit  abandonment  of  the  conserva- 
tion of  matter.  From  this  abstract  consideration,  I  now 
descend  to  the  concrete. 

We  must  suppose  that  cerebral  processes,  if  reduced  to 
their  last  chemical  analysis,  would  be  resolved,  like  all  other 
chemical  processes,  into  the  motion  of  atoms.  Just  as  the 
substance  of  the  brain  is  built  up  by  an  excessively  complex 
grouping  of  individual  atoms,  so  the  functions  of  the  brain 
are  the  physiological  counterpart  of  the  motions  of  these 
atoms.  All  cerebral  phenomena  thus  consist  ultimately 
of  atomic  motions ;  and  any  nervous  activity  is  due  to  a 
particular  kind  of  motion  of  atoms  in  the  brain,  such 
motion  being,  on  the  mechanistic  theory,  in  harmony  with 
the  laws  of  physics,  but  on  the  vitalistic  theory,  not  in 
harmony  with  them.  If  all  matter  is  reducible  to  atoms, 
and  all  energy  to  matter  in  motion,  we  may  look  upon 
an  atom  in  motion  as  the  unit  of  all  physical  phenomena. 
The  direction  of  its  motion  is  controlled  by  the  influence 
of  neighbouring  atoms,  if  we  accept  Newton's  first  law,  viz., 
that  its  direction  of  motion  cannot  change  except  by  reason 
of  an  "  external  impressed  force."  Now  the  vitalist  proceeds 
to  assume  a  new  influence  in  addition  to  that  exerted  by 
neighbouring  atoms,  which,  joining  in  with  these,  produces 
a  resultant  motion  in  a  different  direction  from  what  the 
natural  forces  would  have  produced  alone.  But,  as  I  have 
already  pointed  out,  force  is  only  a  name  for  stating  the 
mutual  influence  exercised  by  atoms  upon  one  another.  The 
assumption  of  a  new  force  involves,  therefore,  the  assumption 
of  new  matter;  nay,  one  of  the  commonest  definitions 


THE  FALLACY  OF  VITALISM  109 

of  matter  is  "  that  which  can  exert,  or  be  acted  upon  by, 
a  force." l  Moreover,  the  allegation  of  a  new  force  is 
absolutely  meaningless,  unless  it  implies  this  new  matter. 
For,  setting  aside  all  theories,  what  is  the  fundamental 
fact  alleged  by  the  neo-vitalists  ?  They  affirm  that  an  atom 
in  motion  may  change  its  direction  of  motion  without 
a  material  cause.  What  right,  then,  have  they  to  use  the 
term  "  force"  to  describe  this  change  of  motion  ?  All  they 
demand  is  that  motion  is  changed  in  direction.  By  saying 
that  a  "vital  force"  is  the  operative  factor,  they  gain 
nothing  whatever  as  regards  explaining  the  change  of 
direction,  except  in  so  far  as  they  assume  the  "vital  force" 
to  have  a  material  origin.  The  use  of  the  word  "  force  "  is 
wholly  unjustifiable ;  it  gives  a  fictitious  appearance  of 
increased  comprehensibility,  which  appearance  can  only 
be  attained  by  deliberately  avoiding  the  consideration  of 
the  connotations  and  meaning  of  the  word  "  force."  It  is  a 
verbal  explanation  ;  that  is  to  say,  it  is  no  explanation  at  all. 
If  the  atom  be  proved  to  change  its  direction  of  motion 
in  the  way  alleged,  this  must  be  accepted  as  an  ultimate 
fact,  and  an  exception  to  Newton's  laws.  The  case  is 
exactly  analogous  to  that  of  a  cannon-ball  moving  through 
space  which  should  suddenly  change  its  direction  of  motion 
at  a  right  angle,  without  any  material  force  or  cause  whatever. 
We  may,  with  the  neo-vitalists,  ascribe  the  change  to  a 
"  celestial  force,"  or  we  may  call  it  a  miracle  ;  we  may  say 
that  God  did  it,  or  that  its  guiding  angel  did  it ;  we  may 
say  what  we  like,  but  all  we  know  is  that  the  direction 
of  motion  is  changed,  and  that  our  mechanics  do  not  apply. 
Hence  it  follows  that,  if  cerebral  processes  involve  some- 
thing more  than  mere  mechanical  interplay,  then  you  must 
assume  one  of  two  things  :  either  that  atoms  alter  their 
velocity  of  motion  without  external  cause,  in  which  case  you 

1  This,,  for  instance,  is  the  definition  given  by  Lord  Kelvin  and 
Professor  Tait  in  their  Treatise  on  Natural  Philosophy. 


110    MODERN  SCIENCE  AND  MATERIALISM 

traverse  the  law  of  conservation  of  energy,  or  that  they 
alter  their  direction  of  motion,  in  which  case  you  traverse 
Newton's  laws  and  the  law  of  conservation  of  matter. 

There  is,  of  course,  no  a  priori  reason  why  Newton's  laws 
should  not  be  traversed.  It  is  conceivable  that,  though  they 
have  been  found  to  hold  good  throughout  every  department 
of  nature  hitherto  investigated,  they  might  yet  fail  in  their 
application  to  the  nervous  system.  But  it  is  very  important 
to  recognize  what  is  really  meant  by  saying  that  they  fail ; 
and  in  order  to  facilitate  that  apprehension,  an  analogy  may 
be  employed. 

Although  we  are  not  yet  aware  of  the  precise  nature  of 
the  nervous  impulse,  yet  we  have  no  reason  to  suppose  that 
it  involves  the  transmission  of  material  particles  along  the 
nerve.  The  substance  of  nervous  tissue  must  be  built  up 
from  the  basis  of  some  kind  of  physiological  unit.  I  do  not 
know  whether  this  unit  is  best  described  as  an  excessively 
complex  molecule,  or  as  a  definite  aggregate  or  combination 
of  such  molecules.  But,  at  all  events,  the  nervous  tissue  owes 
its  peculiar  properties  to  some  specific  type  of  molecule  or 
super- molecule  of  which  it  is  composed,  and  which  consti- 
tutes its  physiological  unit.  This  unit  is  so  constituted 
that,  when  functionally  stimulated,  the  chemical  or  super- 
chemical  change  then  induced  in  it  is  propagated  forwards 
to  neighbouring  molecules.  Each  unit  functions  momentarily, 
and  is  then  restored  very  nearly  to  its  former  state  of  equili- 
brium. Its  functioning  infects  adjacent  units,  which  likewise 
pass  on  the  stimulus  and  themselves  promptly  return  to  their 
original  condition.  In  this  manner,  a  wave  of  chemical, 
electrolytic  or  super-chemical  change  passes  down  a  nerve, 
leaving  scarcely  any  permanent  traces  behind  it,  and  only 
registering  its  ultimate  effect  when  it  reaches  the  extremity 
of  the  nerve.  It  then  passes  into  the  grey  matter  of  the 
nervous  tissue,  where  its  course  is  somewhat  different.  In 
passing  through  the  grey  matter,  the  impulse  apparently 
leaves  behind  it  larger  traces  of  its  passage.  It  progresses 


THE  FALLACY  OF  VITALISM  111 

more  slowly,  owing  probably  to  the  necessity  of  jumping 
numerous  synapses  or  junctions  between  nerve-cells.  There 
are  a  number  of  other  differences  (which  will  shortly  be 
named);  but  there  can  be  no  doubt  that  the  mode  of  trans- 
mission through  the  grey  matter  is  fundamentally  the  same 
as  that  through  a  single  nerve. 

This  transmission  may  be  compared  to  the  passage  of 
an  impulse  down  a  line  of  billiard-balls  in  contact  with  one 
another.  If  we  strike  the  ball  at  one  end  of  the  line  in  the 
direction  of  the  centre  of  the  adjacent  ball,  the  impulse  will 
be  conveyed  down  the  line  till  it  reaches  the  ball  at  the 
remote  end.  This  ball  will  then  move  forwards  with  a 
velocity  proportional  to  the  force  with  which  the  first  ball 
was  struck.  All  the  other  balls,  including  that  struck, 
remain  motionless.  Comparing  the  balls  now  to  the  physio- 
logical units  of  a  nerve,  we  see  that  the  process  is  analogous 
in  the  two  instances.  In  both  cases,  a  stimulus  delivered 
at  one  end  sets  up  a  wave  which  travels  down  the  line 
and  delivers  its  effects  at  the  remote  end.  The  intermediate 
balls,  or  physiological  units,  each  in  turn  are  thrown  into  a 
momentary  state  of  activity,  from  which  they  speedily  revert 
to  their  former  quiescence. 

The  entrance  of  the  current  into  the  grey  matter  of  the 
spinal  cord  and  brain  may  likewise  be  represented  by  a  more 
complex  arrangement  of  billiard-balls.  If,  as  I  assume,  the 
mode  of  propagation  of  the  impulse  is  fundamentally  the 
same  in  the  grey  matter  as  in  the  nerve,  it  may  similarly  be 
represented  by  the  passage  of  mechanical  energy  through  a 
system  of  billiard-balls  in  contact  with  one  another. 

Now  the  mechanistic  theory  affirms  that  any  current 
established  within  the  nervous  system  proceeds  to  its  natural 
physico-chemical  effects.  The  vitalistic  theory  affirms,  on 
the  contrary,  that  a  spiritual  force  co-operating  with  the 
ordinary  material  forces  causes  it  to  issue  in  different  results 
from  those  which  would  have  been  produced  by  the  material 
forces  alone.  Referring  to  the  analogy  of  the  billiard-balls, 


112    MODERN  SCIENCE  AND  MATERIALISM 

the  mechanistic  theory  asserts  that  the  transmission  of  the 
impulse  from  ball  to  ball  follows  the  laws  of  mechanics 
(discovered  or  undiscovered).  The  vitalistic  theory,  on  the 
other  hand,  asserts  that  a  departure  from  mechanical  laws 
takes  place.  This  departure  may  be  visualized  in  various 
ways.  Either  one  ball  striking  another  produces  no  motion 
in  that  other,  and  yet  loses  its  own,  or  a  ball  suddenly 
acquires  an  impetus  of  its  own  without  having  been  struck 
or  acted  upon  by  any  external  impressed  force  whatever, 
or  a  ball  struck  by  its  neighbour  in  its  centre  does  not 
move  off  in  the  line  in  which  it  was  struck,  but  in  another 
line,  as,  for  instance,  at  a  right  angle  to  the  line  in  which 
it  was  struck. 

Now  in  practical  life  we  might  explain  any  of  these 
apparent  anomalies  by  reference  to  imperfections  of  the 
table  or  the  balls,  or  to  friction,  or  some  other  recognized 
natural  agency.  In  such  cases  the  anomaly  is  only  apparent : 
in  reality  the  balls  are  following  their  necessary  mechanical 
course,  and  this  course  is  different  from  what  we  expected 
only  because  we  omitted  to  take  into  consideration  certain 
of  the  mechanical  factors  engaged.  But  all  errors  of  this 
kind  are  excluded  from  vitalistic  hypothesis.  It  is  the 
definite  axiom  of  vitalism  that  the  balls  do  move  in  a 
manner  inconsistent  with  mechanics  —  that  is  the  whole 
difference  between  mechanism  and  vitalism.  The  case  of 
vitalism  may  be  represented  by  that  of  a  billiard-ball  pro- 
ceeding to  move  off  on  its  own  account,  with  a  certain 
velocity  and  direction,  without  any  kind  of  material  cause 
whatever,  known  or  unknown. 

My  purpose  in  adopting  this  analogy  is  to  bring  home 
the  fundamental  inconceivability  of  the  vitalistic  position. 
The  particular  objection  to  mechanism  which  I  am  here 
endeavouring  to  meet,  is  the  difficulty  of  imagining  how 
any  structure  of  a  purely  chemico-mechanical  basis  could 
account  for  the  infinite  varieties  and  complications  of 
human  conduct  and  morals.  Theoretically  any  result  may 


THE  FALLACY  OF  VITALISM  113 

be  achieved  by  a  machine;  but  in  the  present  case  the 
incredible  complexity  required  of  the  machine  is  held  by 
vitalists  to  constitute  a  very  serious  difficulty  in  believing 
in  the  reality  of  the  machine-idea  at  all.  They  do  not 
appear  to  recognize  that  their  own  rival  hypothesis  demands 
a  still  greater  strain  upon  our  credulity.  They  ask  us  in 
effect  to  conceive  a  billiard-ball  rolling  off  without  any 
material  cause.  They  ask  us  to  believe  that  a  cannon-ball 
flying  through  space  may  change  its  direction  of  motion 
without  the  aid  of  any  external  impressed  force.  Such 
propositions  as  these  attain  the  highest  degree  of  incon- 
ceivability possible  to  the  human  mind. 

But  now  a  further  point  arises.  Let  us  suppose  that  the 
hypothesis  of  a  vital  force,  instead  of  being  wholly  and 
unutterably  inconceivable,  were  to  be  recognized  as  a  pos- 
sible factor.  Let  us  for  the  sake  of  argument  accept  it, 
and  see  to  what  extent  it  assists  us.  The  data  furnished 
to  us  by  the  nervous  system  may  be  typically  represented 
as  follows.  A  stimulus,  more  or  less  complicated,  affects 
the  sense-organs  or  terminations  of  afferent  nerves.  It  is 
thence  conveyed  to  the  central  parts  of  the  nervous  system, 
from  whence,  after  a  longer  or  shorter  period,  it  issues  in 
currents  along  efferent  nerves,  producing  some  more  or  less 
complicated  muscular  acts.  In  a  number  of  cases,  as,  for 
instance,  where  ethical  or  aesthetic  judgments  are  formed, 
the  central  process  is  deemed  by  vitalists  too  complex  to 
be  explicable  on  mechanical  principles. 

Now  let  us  return  once  more  to  the  billiard-table,  over 
which  is  scattered  a  collection  of  balls.  The  nervous  stimulus 
is  represented  by  a  new  ball  entering  the  system,  and  there 
setting  up  a  commotion,  while  the  ultimate  effect  is  regis- 
tered in  two  or  three  balls  at  the  remote  end  of  the  system, 
which  travel  off,  and  drain  away  the  energy  brought  in  by 
the  stimulus.  Our  data,  therefore,  consist  of  a  knowledge 
of  the  incoming  ball  (its  mass,  velocity  and  direction),  and 
also  a  knowledge  of  the  outgoing  balls.  Our  problem  is  to 


114    MODERN  SCIENCE  AND  MATERIALISM 

ascertain  how  one  gives  rise  to  the  other.  As  already 
stated,  the  mechanistic  solution  supposes  that  the  end-effect 
is  mechanically  attained  by  means  of  the  impulses  set  up 
by  the  incoming  ball.  The  vitalistic  solution,  while  admit- 
ting the  succession  of  mechanical  impacts,  denies  that  they 
are  adequate  to  produce  the  end-effect,  and  affirms  that 
this  effect  is  attained  by  means  of  one  or  more  other  balls 
in  the  midst  of  the  system  which  take  on  a  supernatural 
movement  of  their  own.  This  motion,  joined  to  the  motion 
mechanically  produced,  is  deemed  capable  of  producing  the 
end-effect. 

Does  not  this  hypothesis  throw  a  greater  strain  upon  our 
imagination  than  the  purely  mechanical  hypothesis  ?  Con- 
sider the  astonishing  nicety  of  calculation  required  to  decide 
the  introduced  supernatural  motion.  It  is  not  as  though 
that  motion  alone  was  to  produce  the  end- effect :  it  has  to 
modify  ordinary  mechanical  motion,  already  highly  complex, 
in  such  a  way  that  the  desired  end-effect  may  be  produced. 
The  power  which  controls  the  supernatural  added  motion 
has  not  only  to  estimate  the  result  required,  it  has  also  to 
estimate  the  existing  mechanical  motion,  and  the  results 
which  would  be  wrought  by  that  motion  if  left  to  its  natural 
course.  It  has  then  to  decide  what  degree  of  modification  has 
to  be  inserted  in  the  mechanical  motion.  Supposing  that  we 
have  two  balls  at  opposite  ends  of  the  billiard-table,  and  that 
we  have  to  strike  one  with  a  cue  in  such  a  way  that  it  shall 
hit  the  other  at  a  given  velocity  and  alignment.  Mechanism 
assumes  that  the  ball  is  struck  in  the  correct  way  from  the 
first.  Vitalism  assumes  that  it  is  incorrectly  struck,  and  that 
it  moves  forwards  at  a  wrong  velocity  and  alignment.  Midway 
in  its  career,  however,  the  vital  force  comes  into  contact  with 
it,  and  this  contact  is  so  delicately  arranged  that  it  produces 
in  the  original  ball  just  the  very  modification  of  motion  needed 
to  cause  it  to  strike  the  final  ball  at  the  exact  angle  and 
velocity  contemplated.  This  surely  is  a  far  more  remarkable 
event  than  if  the  first  ball  had  been  correctly  struck  at  first. 


THE  FALLACY  OF  VITALISM  115 

Very  nearly  all  the  arguments  adduced  against  mechanism 
at  the  present  day  are  based  upon  the  statement  that  "  it  is 
impossible  to  understand  "  how  such  and  such  an  event  could 
be  produced  by  mechanical  means.  I  therefore  wished  at  the 
outset  to  meet  that  argument  by  showing  that  it  is  much 
more  deadly  to  vitalistic  than  to  mechanistic  theories.  I 
have  endeavoured  to  show,  in  the  first  place,  that  the  very 
notion  of  a  vital  force  involves  a  more  profound  inconceivability 
than  anything  in  the  whole  range  of  mechanism.  In  the 
second  place,  I  have  endeavoured  to  show  that,  even  if  the 
vital  force  were  a  conceivable  and  a  true  agency,  its  operation 
would  still  involve  a  far  higher  complexity  and  elaboration — 
and  therefore  a  greater  inconceivability — than  the  simple 
operation  of  known  mechanical  forces.  The  vital  force  is  not 
only  inconceivable  by  its  very  nature,  but  if  it  were  con- 
ceivable, its  sole  effect  would  be  enormously  to  complicate 
the  immense  difficulties  of  the  problem  before  us.  We  must 
then  recognize  that  the  difficulty  felt  by  vitalists  does  not 
apply  to  the  solution  of  mechanism,  but  to  the  facts  themselves. 
The  really  startling  thing  is  that  these  events  do  happen. 
That  would  indeed  be  enough  to  excite  incredulity,  did  we 
not  witness  them  at  every  moment  of  our  lives.  Given  the 
facts,  there  is  no  further  difficulty  in  accounting  for  them 
mechanically :  if  we  try  to  account  for  them  supernaturally, 
we  are  simply  endeavouring  to  smoothe  away  difficult  facts 
by  the  fabrication  of  inconceivable  theories. 

The  vitalists  have  been  apt  to  proceed  upon  the  assumption 
that  the  burden  of  proof  lies  upon  mechanism,  and  that  until 
mechanism  shall  be  definitely  established  by  experimental 
methods,  vitalism  holds  the  field.  It  is,  no  doubt,  quite  true 
that  the  question  cannot  be  settled  out  of  hand  by  recourse 
to  observation  or  experiment;  if  it  could  be,  there  would 
naturally  be  no  occasion  for  discussion  of  the  subject.  The 
foregoing  argument  is,  therefore,  intended  to  show  that,  if  we 
are  forced  to  the  examination  of  a  priori  probabilities,  every 
sort  of  difficulty,  or  rather  inconceivability,  blocks  the  way  to 


116    MODERN  SCIENCE  AND  MATERIALISM 

a  belief  in  vitalism.  Still  more  powerful  considerations, 
however,  may  be  urged  in  favour  of  the  view  that  mechanism 
is  the  normal  and  natural  theory  of  science,  while  vitalism  is 
not  admissible  even  as  an  hypothesis. 

I  have  already  dilated  upon  the  fact  that  the  human  mind 
ten.ds  to  explain  events  from  two  opposite  points  of  view, 
materialistic  and  spiritualistic.  I  have  pointed  out  that  in 
primitive  times  the  spiritualistic  methods  were  in  the  ascend- 
ancy, and  that  materialistic  explanations  were  only  invoked 
in  those  simple  cases  where  their  application  was  obvious  and 
undeniable.  With  the  growth  of  science  and  civilization, 
an  ever-increasing  category  of  events  became  explicable  on 
mechanical  principles,  and  the  spiritualistic  principles  by 
which  they  were  formerly  accounted  for  fell  into  disrepute. 
The  advances  of  materialism,  though  always  unpopular,  have 
always  been  successful,  and  the  predominance  of  materialism 
at  any  epoch  affords  the  truest  possible  index  to  the  degree 
of  civilization  at  that  epoch.  Materialism  was  at  its  height 
at  the  zenith  of  ancient  Greek  civilization.  It  declined  with 
the  growth  of  Christianity  at  the  beginning  of  the  Middle 
Ages.  It  almost  completely  vanished — vanished  to  a  degree 
that  is  now  entirely  inconceivable  to  us — during  the  blackest 
period  of  mediaeval  times.  It  revived  with  the  renascence  of 
science  and  philosophy.  It  has  since  grown  steadily,  notwith- 
standing the  animosity  and  persecution  of  religion,  and  in 
the  present  century  it  has  reached  a  higher  point  than  ever 
before  in  the  history  of  the  world.  The  domain  of  spiritual- 
istic methods  formerly  included  every  branch  of  nature.  By 
degrees  the  inorganic  realm  became  emancipated,  until  now, 
by  universal  consent,  all  events  of  inorganic  character  are  inter- 
preted by  mechanical  methods.  For  a  long  time  the  rise 
of  materialism  scarcely  touched  the  organic  realm.  Then 
gradually  organic  processes  fell  under  the  materialistic  law 
of  interpretation.  Spallanzani  disproved  the  spiritual  theory 
of  the  process  of  reproduction.  Lavoisier  showed  that  bodily 
heat  was  due  to  oxidation.  Up  till  that  time  spiritual 


THE  FALLACY  OF  VITALISM  117 

theories  of  life  had  remained  almost  unquestioned  ;  after  that 
time  the  opposite  schools  of  vitalism  and  mechanism  came 
into  sharp  conflict.  Materialistic  principles  were  found  to 
apply  to  one  after  another  of  organic  processes.  The  organ- 
ism as  a  whole  was  proved  to  be  subject  to  the  great  laws  of 
physics.  Matter  was  neither  created  nor  destroyed  in  it. 
The  energy  given  out  from  it  was  identical  in  quantity  with 
that  supplied  to  it.  Organic  products,  such  as  urea,  were 
manufactured  in  the  laboratories.  At  length  it  was  recog- 
nized that  all  the  organic  processes,  to  which  the  experimental 
method  had  hitherto  been  applicable,  were  based  upon 
mechanical  forces.  There  remained  the  nervous  system, 
which  long  seemed  too  complex  for  experimental  investi- 
gation, and  which  was  thereupon  proclaimed  as  the  true 
sphere  of  spiritual  activities.  But  after  a  time,  experiment 
began  to  invade  even  this  sanctified  and  difficult  region. 
Reflex  action  was  the  first  to  be  investigated ;  and  it  was 
soon  found  that  reflex  action  was  wholly  and  completely 
mechanical  in  nature.  Further  researches  disclosed  the  fact 
that  the  nervous  system  appeared  to  be  built  up  wholly  on 
the  reflex  principle ;  it  consisted  of  a  vast  and  inconceivably 
complex  multitude  of  reflex  arcs,  combined  and  superimposed 
upon  one  another,  with  infinite  variety  of  form  and  position. 
And  this  is  how  the  problem  stands  to-day.  If  it  is  true 
that  mechanism  has  not  yet  been  witnessed  by  actual  obser- 
vation of  the  incredibly  intricate  regions  of  the  brain,  it  is 
nevertheless  true  that  mechanism  approaches  towards  that 
fortress  as  near  as  the  perfection  of  human  instruments  will 
allow.  It  has  already  conquered  the  simplest  forms  of  nervous 
activity,  and  it  has  shown  that  all  the  more  complex  forms 
are  compounded  from  the  simplest.  This  single  argument 
seems  by  itself  to  constitute  an  overwhelming  presumption 
in  favour  of  mechanism,  and  we  have  to  remember  that  the 
argument  is  only  one  among  numerous  others,  all  converging 
to  the  same  result.  It  seems,  therefore,  certain  that  any  truly 
unbiassed  student  will  regard  vitalism  as  so  excessively 


118    MODERN  SCIENCE  AND  MATERIALISM 

improbable  an  hypothesis,  that  it  could  scarcely  even  be 
suggested  without  the  support  of  overwhelming  evidence. 
And  when  the  student  further  ascertains,  not  merely  that  it 
is  supported  by  no  evidence  of  any  kind  whatsoever,  but  that 
the  whole  idea  of  it,  when  consistently  thought  out,  proves 
to  involve  the  greatest  inconceivability  ever  dreamt  of  by 
man,  he  will  perhaps  regard  the  claim  of  vitalism  to  escape 
the  burden  of  proof  as  one  of  the  most  presumptuous  and 
regrettable  incidents  in  the  whole  history  of  human  error 
and  superstition. 

But  the  believer  in  vitalism  (it  need  hardly  be  said)  is  not 
unbiassed.  It  is  obvious  that,  whatever  may  be  the  reason, 
humanity  evinces  a  strong  bias  in  favour  of  any  kind  of 
spiritual  belief.  I  do  not  allude  merely  to  the  wide  generality 
of  religious  beliefs.  Those  beliefs  are,  indeed,  mainly  erro- 
neous, as  will  be  admitted  by  nearly  all,  even  of  those  who 
hold  them.  For  whatever  sect  or  religion  we  belong  to,  we 
are  in  a  minority  as  compared  with  the  totality  of  other 
religions  prevailing  in  the  world ;  and  if  we  believe  that  our 
own  religion  is  the  true  one,  we  ipso  facto  believe  that  the 
majority  of  mankind  are  in  error.  It  is  less  to  this  fact  that 
I  refer,  however,  than  to  the  fact  that  every  materialistic 
advance  has  been  met  with  the  most  vigorous  opposition  of 
the  Church,  the  people,  and  often  the  civil  government. 
The  history  of  the  progress  of  materialistic  science  is  a  history 
of  persecution,  and  however  we  may  account  for  it,  the  fact 
remains  that  the  normal  mind  has  a  strong  disinclination 
towards  materialistic  doctrines,  or,  in  other  words,  a  strong 
bias  in  favour  of  spiritualistic  doctrines.  It  is  this  bias  which 
causes  vitalism  still  to  be  maintained  and  supported,  not- 
withstanding the  extreme  discredit  into  which  science  and 
logic  have  brought  it. 

On  the  other  hand,  the  belief  in  vitalism  is  least  where 
knowledge  of  the  facts  is  greatest.  The  problem  of  vitalism 
and  mechanism  is  a  problem  of  physiology ;  and  it  is  cer- 
tain that  of  all  classes  in  the  community,  the  physiologists 


THE  FALLACY  OF  VITALISM  119 

constitute  that  with  which  vitalism  finds  the  smallest  favour. 
Furthermore,  it  is  essentially  a  problem  of  the  physiology  of 
the  nervous  system,  and  it  may  very  safely  be  affirmed  that, 
among  the  physiologists  who  have  devoted  special  attention 
to  the  nervous  system,  over  ninety  per  cent,  are  warm  ad- 
herents of  extreme  mechanism.  Belief  in  mechanism  in  any 
class  is  proportional  to  the  knowledge  of  the  facts  prevailing 
in  that  class,  and  it  is  a  remarkable  testimony  to  the  strength 
of  the  evidence  in  favour  of  mechanism,  that  those  possessing 
special  knowledge  of  that  evidence  should  have  been  con- 
verted from  the  powerful  bias  with  which  they,  like  other 
men,  originally  started. 

No  doubt  this  bias  is  in  part  founded  upon  a  desire  to 
believe  in  freedom  of  will,  and  moral  responsibility,  and 
other  cherished  convictions  which  a  poor,  short-sighted  logic 
supposes  to  be  affected  by  determinism.  To  this  subject  I 
shall  refer  later.  Men  affirm  that  they  are  free  to  do  what 
they  like  ;  and,  finding  themselves  unable  to  calculate  what 
other  men  will  do  in  particular  circumstances,  they  declare 
that  there  exists  in  the  spring  of  human  activities  an  element 
of  inde termination  which  is  wholly  unprophesiable  and  arbi- 
trary, and  never  can  be  brought  within  the  range  of  a  constant 
scientific  formula.  This,  again,  is  in  contradiction  with  the 
facts.  It  is  true  that,  in  the  case  of  one  man,  it  is  often  quite 
impossible  to  say  what  he  will  do  in  some  particular  collocation 
of  circumstances.  A  brain  is  so  complex  a  thing  that  one 
cannot  in  every  instance  prophesy  what  muscular  contractions 
will  ensue  from  a  given  stimulus.  That  truth  does  not  consti- 
tute any  evidence  of  an  indeterminate  factor,  but  only  of  the 
complexity  of  the  machine.  Moreover,  the  more  intimately 
acquainted  we  are  with  the  man,  the  more  accurately  shall  we 
be  able  to  forecast  his  behaviour.  Knowing  the  'kind  of 
activities  to  which  he  has  been  prone  in  the  past,  we  are  able 
to  form,  by  inductive  methods,  an  approximate  opinion  as 
to  what  he  will  do  in  given  circumstances.  This  fact  alone 
suffices  to  dispel  the  notion  of  an  indeterminate  factor. 


120    MODERN  SCIENCE  AND  MATERIALISM 

Still  more  evident  is  this  truth  when  dealing  with  men 
en  masse.  We  are  very  often  able  to  prophesy  within  close 
limits  what  the  public  will  do  in  special  circumstances.  We 
can  form  a  very  accurate  forecast  as  to  the  number  of  suicides 
or  the  number  of  marriages  that  will  occur  in  the  course  of 
a  year.  We  can  predict  what  effect  the  price  of  corn  will 
have  upon  these  figures.  The  more  accurate  our  knowledge, 
the  more  certainly  can  we  prophesy. 

Now  all  this  militates  strongly  against  the  idea  that  there 
is  an  indeterminate  factor  in  human  behaviour.  Such  a 
belief  is  indeed  only  consonant  with  a  profound  ignorance  of 
humanity.  If  indetermination  was  true,  we  could  not  reduce 
human  conduct  to  rules  as  we  do ;  we  could  not  embody  it 
in  formulae  or  geometrical  curves  ;  statistics  would  afford  no 
basis  for  arguing  from  the  past  to  the  future.  The  more  we 
study,  the  more  industriously  we  collect  statistics,  the  more 
deeply  we  analyze  motives  and  factors,  the  more  accurately 
are  we  able  to  forecast  the  behaviour  of  men  in  bulk.  With- 
out this  laboriously  accumulated  knowledge,  of  course  men 
were  bound  to  believe  in  an  indeterminate  element ;  for  then 
nothing  was  prophesiable,  all  was  as  fickle  and  arbitrary  as 
the  winds  of  heaven.  But  as  the  knowledge  increases,  the 
fickleness  vanishes ;  human  conduct  falls,  like  all  other 
natural  events,  into  a  recognized  and  regular  system.  In 
proportion  to  our  knowledge  and  analysis  of  the  past,  we  can 
prophesy  the  future  ;  and  if  we  can  never  attain  absolute 
accuracy,  the  reason  is  that,  as  with  the  winds,  we  can  never 
co-ordinate  the  whole  of  the  factors  engaged,  we  can  never 
attain  to  a  perfect  knowledge  of  the  past. 

If  the  entire  activity  of  all  animals,  including  Man.  is  due 
to  physico-chemical  forces,  and  if  in  consequence  every 
animal  is  an  excessively  complex  machine,  the  very  important 
problem  arises  as  to  the  relation  of  consciousness  to  this 
machine.  We  are  accustomed  to  think  of  consciousness  as  a 
spiritual  and  not  a  material  manifestation ;  and  we  know  by 
constant  and  immediate  experience  that  a  conscious  effort  can 


THE  FALLACY  OF  VITALISM  121 

produce  a  bodily  action,  that  is,  a  spiritual  antecedent  give 
rise  to  a  bodily  consequent.  We  are  faced  with  an  apparent 
paradox :  on  the  one  hand,  we  know  by  direct  introspection 
that  an  operation  of  mind  can  cause  a  movement  of  body ;  on 
the  other  hand,  we  know  that  every  bodily  movement  is  due 
to  some  constellation  of  purely  material  or  physical  forces, 
not  capable  of  modification  by  any  spiritual  factor.  To  meet 
this  difficulty,  there  have  been  elaborated  the  various  so- 
called  theories  of  parallelism  between  mind  and  brain.  Of 
these  theories,  the  most  popular,  as  well  as  the  most  plausible, 
is  Huxley's  theory  of  epiphenomenalism,  according  to  which 
mental  processes  are  invariable  but  inert  accompaniments  of 
certain  cerebral  processes.  For  every  mental  state,  such,  for 
instance,  as  a  desire  to  do  something,  there  is  a  corresponding 
cerebral  state,  and  the  two  states  vary  together  in  an 
absolutely  parallel  manner.  When  some  act  is  performed, 
therefore,  on  the  one  hand  it  is  preceded  by  the  subjective 
desire  to  perform  the  act ;  this  subjective  desire  is  in 
itself  wholly  impotent,  but  it  is  accompanied  by  the  corre- 
sponding cerebral  condition,  and  this  condition  gives  rise  to 
the  act  by  physico-chemical  necessary  laws.  The  subjective 
shadow  of  mind  has  no  causal  influence  whatever  in  the 
process.  It  is  an  absolute  superfluity,  and  the  act  would  be 
performed  just  the  same  whether  the  subjective  accompani- 
ment was  present  or  not.  One  mental  state  cannot  even 
cause  the  next ;  the  cerebral  process  underlying  one  mental 
state  gives  rise  to  another  cerebral  process  underlying  a  new 
mental  state.  Thus,  while  on  the  surface  one  mental  state 
appears  to  have  caused  another,  the  true  causal  sequence  has 
been  the  unseen  but  material  alterations  in  the  brain,  which 
carry  with  them  parallel  alterations  in  what  is  called  the 
mind. 

I  propose  to  show  in  Chapter  VI  that  epiphenomenalism, 
although  the  most  plausible  theory  attainable  to  dualism, 
is  nevertheless  untenable.  We  speak  of  the  mind  as  though 
it  were  a  thing,  and  since  it  is  not  a  material  thing,  it  is 


122    MODERN  SCIENCE  AND  MATERIALISM 

regarded  as  possessing  a  spiritual  consistency.  If  we  can, 
by  a  great  effort,  shake  off  this  paralyzing  prejudice — a 
prejudice  which  has  been  immensely  fortified  and  refined 
by  the  whole  Kantian  philosophy — we  may  still  preserve 
sufficient  elasticity  to  perceive  that  we  know  of  no  such 
thing  as  mind ;  we  know  only  of  particular  states  of 
consciousness,  kaleidoscopically  varying  from  moment  to 
moment.  What  is  a  state  of  consciousness  ?  The  untrained 
mind  will,  of  course,  immediately  hypostatize  it,  and  call  it 
a  thing.  Let  us,  however,  call  it  a  process,  and  instead  of 
regarding  it  as  a  thin  and  shadowy  accompaniment  of 
certain  cerebral  processes,  let  us  boldly  identify  it  with 
those  processes,  and  say  that  it  is  one  and  the  same. 
Immediately  all  difficulties  vanish.  You  affirm  that  you 
move  your  arm  by  an  act  of  will ;  I  affirm  that  you  move 
it  by  a  cerebral  process.  We  are  both  right ;  for  the  act 
of  will  is  the  cerebral  process  itself. 

For  the  present  I  wish  to  do  no  more  than  state  this 
theory.  I  propose  to  justify  it  in  the  final  chapter  of  this 
book.  All  that  need  now  be  accepted  is  that  there  is 
some  sort  of  immediate  and  invariable  correlation  between 
mental  and  cerebral  processes,  a  point-to-point  corre- 
spondence, so  that  any  one  kind  of  mental  condition 
necessarily  implies  some  specifically  corresponding  kind  of 
cerebral  condition.  Whether  we  regard  the  relation  as  one 
of  identity  or  of  simple  parallelism  is  of  little  importance 
at  the  present  stage.  The  law  of  correlation,  in  either  case, 
insists  that  psychology  is  subordinate  to  physiology,  and 
that  if  the  physiology  of  the  brain  and  nervous  system 
were  entirely  understood,  the  coexistences  and  sequences 
of  mental  states  would  also  become  clear.  It  appears,  more- 
over, that,  even  in  the  existing  state  of  physiology,  a  great 
many  mental  processes  are  explained  far  more  easily  by 
reference  to  physiology  than  by  pure  psychology  alone.  It 
is  to  the  physiological  aspects  of  the  mind  that  I  shall 
devote  the  remainder  of  this  chapter. 


THE  FALLACY  OF  VITALISM  123 

Psychologists  divide  mental  processes  into  three  main 
groups  :  intellect,  emotion,  and  will.  The  definition  of 
these  groups  is  not  easy.  Emotion  seems  to  possess  inten- 
sity as  its  fundamental  characteristic.  Although  it  is 
commonly  associated  with  pleasure  and  pain,  there  is  prob- 
ably no  necessity  for  such  a  relation.  Some  very  powerful 
emotions  —  such,  for  instance,  as  surprise  —  may  be  free  from 
any  pleasurable  or  painful  colouring. 


an  intensive  nervous  condition,  and  physiologically  we  may 
suppose  it  to  be  characterized  by  extremely  rapid  molecular 
change,  or  by  intense  functioning  in  the  region  of  the 
nervous  system  with  which  it  is  correlated. 

Intellect,  on  the  other  hand,  is  mainly  characterized  by 
cxtensity.  Intellectual  processes  take  place  by  means  of 
association.  In  the  brain  we  must  suppose  a  network  of 
associative  bonds  to  be  the  correlate  of  intellect.  Innu- 
merable nerve-cells  become  bound  together  by  threads  of 
communication,  or  by  suppression  of  resistance  at  the 
synapses,  and  function  jointly.  These  lines  of  com- 
munication are  not  so  much  material  links  as  passages 
of  easy  transit,  which  enable  large  areas  to  function  as 
consolidated  single  units. 

The  mental  category  of  will  corresponds  to  the  cerebral 
process  by  which  muscular  activity  is  initiated  in  certain 
kinds  of  complex  situations.  All  these  main  divisions  of 
the  mind  are  characteristic  of  the  higher  animals  only. 
They  are  all  three  highly  evolved  and  differentiated  out 
from  one  common  origin.  In  the  most  elementary  forms 
of  life,  the  organism  represents  a  little  storehouse  of  energy. 
There  is  no  nervous  system,  but  the  entire  protoplasm 
possesses  in  a  rudimentary  degree  the  properties  of  nerve. 
The  corresponding  rudimentary  consciousness  which  we 
must  attribute  to  these  animals  is  therefore  correlated,  not 
with  the  functioning  of  any  specialized  tissue,  but  with 
the  entire  body  of  the  animal.  At  first  an  external  stimulus 
causes  contraction,  and  this  must  be  regarded,  not  only  as 


124    MODERN  SCIENCE  AND  MATERIALISM 

the  archetype  of  all  nervous  action,  but  also  as  the  begin- 
ning of  all  conscious  processes.  Later  in  evolution,  the 
stimulus  is  conveyed  to  a  central  exchange,  from  whence 
it  emerges  to  a  particular  portion  of  the  body,  which 
portion  alone  contracts.  We  here  have  at  least  five  stages 
in  the  process :  stimulus,  afferent  conduction,  central  process, 
efferent  conduction,  and  contraction.  From  these  rudiments, 
the  whole  of  the  higher  consciousness  of  Man  is  ultimately 
evolved. 

In  the  main  the  differentiation  of  various  types  of  con- 
sciousness is  due  to  the  enormous  elaboration  of  the  central 
process.  When  the  stimulus,  on  reaching  the  central 
ganglia,  there  sets  up  very  intensive  processes  with  vague 
boundaries,  we  have  what  is  called  emotion.  When,  on  the 
other  hand,  it  sets  up  very  extensive  processes  with 
relatively  precise  boundaries,  we  have  what  is  called  intellec- 
tion. When  it  passes  rapidly  through  the  centre,  without 
setting  up  any  unusual  activity,  we  have  to  do  with  reflex 
or  other  automatic  action.  The  fundamental  fact  about 
nervous  activity  is  always  a  stimulus,  afferent  conduction, 
central  process,  efferent  conduction,  muscular  or  glandular 
action.  In  simple  animals,  these  various  elements  are  tolerably 
obvious.  In  complex  animals  they  are  not.  The  central 
process  becomes  so  elaborate  as  often  completely  to  obscure 
the  fundamental  sequence  of  events ;  it  is  often  impossible  to 
name  the  stimulus  or  the  final  action.  The  activity  of  the 
nervous  system  is  concentrated  to  a  high  degree  in  the 
central  regions.  The  cerebral  hemispheres  absorb  the  powers 
of  the  system  ;  the  other  elements  in  the  chain  of  events 
are  swamped  and  lost  sight  of. 

The  evolution  of  the  nervous  system,  and  hence  of 
conscious  processes,  does  not  betray,  therefore,  any  departure 
from  the  original  scheme,  in  which  a  stimulus  from  without 
gives  rise  to  conduction,  central  process,  further  conduction, 
and  finally  action.  The  difference  between  the  primitive 
and  developed  nervous  systems  is  found  mainly  in  the  fact 


THE  FALLACY  OF  VITALISM  125 

that  in  the  primitive  system  the  central  process  is  com- 
paratively insignificant,  whereas  in  the  developed  system 
the  central  process  overwhelms  the  rest,  and  is  very  often 
the  only  discernible  process  occurring.  Thus  in  emotion  the 
incoming  currents  set  up  a  process  of  intensive  molecular 
change  in  the  central  regions.  In  intellection,  the  central 
activity  is  less  violent,  but  far  more  definite  and  precise  :  it 
involves  extensive  molecular  change.  In  reflex  action  and 
simple  nervous  processes  the  impulse  may  run  through  the 
central  regions  without  causing  any  great  commotion  there, 
as  in  primitive  animals.  Primitive  animals  can  have  only 
one  kind  of  consciousness,  subject  only  to  slight  variation, 
because  there  is  little  variation  in  their  central  processes, 
which,  so  to  speak,  are  neither  deep  enough  to  constitute 
emotion,  nor  wide  enough  to  constitute  intellect. 

In  substantiation  of  these  various  propositions,  I  shall 
proceed  by  the  institution  of  two  sets  of  comparisons.  In 
the  first  place,  I  shall  compare  the  conductivity  of  a  simple 
nerve  with  the  conductivity  of  a  reflex-arc.  In  the  second 
place,  I  shall  compare  elementary  conscious  processes  with 
advanced  [conscious  processes.  The  main  difference  between 
a  nerve-trunk  and  a  reflex-arc  is  that  the  former  includes 
no  central  grey  matter,  whereas  the  latter  does.  The  grey 
matter  of  a  reflex-arc  must  contain  at  least  one  synapse  as 
a  theoretical  minimum.  Moreover,  seeing  that  the  whole 
nervous  system  is  built  up  by  a  multi-composition  of  the 
reflex  principle,  it  is  a  sure  assumption  that  the  highest 
nervous  processes  differ  from  the  process  in  the  reflex-arc  in 
the  same  way  that  conductivity  through  the  reflex-arc  differs 
from  nerve-trunk  conductivity.  In  the  highest  nervous 
processes  the  grey  matter  is  enormously  increased,  and  the 
impulse  has  to  be  conveyed  past  a  multitude  of  synapses.  It 
follows  that  the  difference  of  these  highest  nervous  processes 
from  nerve-trunk  conduction  is  of  the  same  kind,  though 
greatly  intensified,  as  the  difference  of  reflex-arc  conduction 
from  nerve-trunk  conduction.  If,  as  I  have  said,  there  is 


126    MODERN  SCIENCE  AND  MATERIALISM 

a  point-to-point  correspondence  between  mental  and  cerebral 
processes,  it  follows  further  that  the  differences  between  the 
higher  and  lower  mental  processes  should  present  an  exact 
counterpart  of  the  differences  between  reflex-arc  conduction 
and  nerve-trunk  conduction.  Let  us  now  inquire  whether 
this  expectation  is  justified  by  the  facts.  I  shall  deal  in  turn 
with  the  eleven  salient  points  of  difference  between  reflex-arc 
conduction  and  nerve-trunk  conduction,  as  given  by  Prof. 
Sherrington  in  his  Integrative  Action  of  the  Nervous  System. 
The  general  purpose  is  to  indicate  the  correspondence 
existing  between  nervous  activity  and  mental  activity.  Prof. 
Sherrington  enumerates  the  differences  between  a  higher  and 
a  lower  form  of  nervous  activity.  This  is  the  nervous 
aspect.  To  each  of  his  eleven  points  of  differentiation  I 
append  the  mental  aspect,  with  a  view  to  showing  that  mental 
complication  and  nervous  complication  pursue  absolutely 
parallel  paths. 


Nervous  Aspect. 
(As  stated  by  Prof. 

Sherrington.) 
(1)  Conduction  in  re- 
flex-arcs is  slower  than  in 
nerve-trunks. 


Mental  Aspect. 


Higher  mental  operations  are 
slower  than  the  simple  ones. 
Intellect  is  slower  than  instinct ; 
voluntary  action  slower  than 
automatic  action. 


(2)  In  reflex-arcs  there 
is  less  close  correspondence 
between  the  moment  of 
cessation  of  stimulus  and 
the  moment  of  cessation 
of  end-effect ;  there  is  a 
marked  after-discharge. 


The  higher  manifestations  of 
mind  have  grown  out  of  all  rela- 
tion to  their  stimulus  and  end- 
effect.  Intellectual  operations  may 
be  initiated  by  a  stimulus  or  set  of 
stimuli  received  long  previously, 
and  they  may  issue  in  action  only 
after  a  protracted  period.  In 


THE  FALLACY  OF  VITALISM 

Nervous  Aspect. 


127 


(3)  Less    close    corre- 
spondence in  reflex-arcs, 
between  rhythm  of  stim- 
ulus and  rhythm  of  end- 
effect. 

(4)  In    the    reflex-arc 
there  is  less  close  corre- 
spondence   between    the 
grading  of  intensity   of 
the    stimulus    and    the 
grading   of  intensity   of 
the  end-effect. 


(5)  The   reflex-arc,  as 
compared  with  a  nerve- 
trunk,  presents  consider- 
able   resistance    to     the 
passage  of  a  single  nerve 
impulse,  but  a  resistance 
easily  forced  by  a  succes- 
sion of  impulses. 

(6)  Irreversibility     of 
direction    in    reflex-arcs, 
as  against  reversibility  in 
nerve-trunks. 


Mental  Aspect. 
lower  mental  operations  there  is 
a  far  closer  time-correspondence 
between  stimulus  and  reaction. 

The   mental   homologue  is  as 
noted  above. 


A  most  marked  characteristic 
of  higher  consciousness.  So  slight 
a  stimulus  as  a  short  sentence  or 
even  a  word,  softly  applied  near 
the  auditory  nerve,  may  produce 
the  most  violent  mental  reaction, 
whereas  an  expected  explosion 
near  by  may  have  very  small 
effect.  In  lower  mental  types, 
no  such  incongruity  exists  between 
stimulus  and  reaction. 

The  mental  correlate  of  this  is 
found  in  the  capacity  of  the  higher 
regions  of  the  mind  for  education. 
Repetition  is  one  of  the  most 
essential  requirements  for  learn- 
ing. In  the  case  of  instinct,  on 
the  other  hand,  repetition  has 
comparatively  slight  effect. 

The  application  of  this  to  con- 
scious processes  is  obvious. 


128    MODERN  SCIENCE  AND  MATERIALISM 


Nervous  Aspect. 
(7)  Fatigability   as 
against  relative  infatiga- 
bility  in  nerve-trunks. 


(8)  Greater  variability 
of  the  threshold  value  of 
the  stimulus. 


(9)  Refractory  period, 
"  Bahnung,"  inhibition, 
and  shock. 


(10)  Much  greater 
dependence  on  blood-cir- 
culation, oxygen,  etc.,  of 
reflex-arcs  than  nerve- 
trunks. 


(11)  Much  greater  sus- 
ceptibility to  various 
drugs,  such  as  anaesthe- 
tics. 


Mental  Aspect. 

The  higher  processes  of  intellect 
and  emotion  are  very  exhausting, 
and  induce  fatigue  far  earlier  than 
the  lower  conscious  processes. 

Mental  processes  are  called 
forth  by  stimuli,  varying  from 
those  that  are  so  great  as  scarcely 
to  be  bearable,  down  to  those  that 
are  so  small  as  to  be  far  beneath 
the  power  of  measurement  (e.  g. 
olfactory  stimuli). 

All  these  are  eminently  char- 
acteristic of  the  higher  mental 
processes.  Inhibition  and  "  Bah- 
nung "  (the  converse  of  inhibition) 
are  the  main  features  of  the  higher 
mental  process  called  attention. 
They  are  enormously  involved  in 
emotion,  as  well  as  in  intellect. 

All  the  higher  mental  processes 
are  instantly  dependent  on  these 
requisites;  and  impoverishment 
of  the  blood-supply  has  a  marked 
effect  in  reducing  the  power  to 
support  either  emotion  or  intel- 
lect. 

Alcohol  temporarily  destroys 
the  higher  mental  powers,  before 
it  reaches  the  lower.  Chloroform 
wholly  blots  out  the  higher  men- 
tal life,  while  yet  the  lower  reflexes 
remain  intact. 


THE  FALLACY  OF  VITALISM  129 

From  these  eleven  points  of  comparison,  we  see  that  the 
higher  mental  processes  differ  from  the  lower  in  precisely 
the  same  way  that  the  reflex-arc  differs  from  the  nerve-trunk. 
The  higher  mental  processes  are  correlated  with  the  develop- 
ment of  grey  matter  in  the  brain,  or  at  least  with  the 
complexity  of  nerve-cells  and  synapses  which  characterize 
that  grey  matter.  Thus  we  have  on  the  physical  side  a 
series  of  functional  units  of  increasing  complexity — nerve- 
trunk,  reflex-arc,  central  nervous  system.  On  the  mental  side 
there  is  a  corresponding  series  of  ascending  complexity — 
automatic  action,  instinct,  and  fully  developed  intellect  or 
emotion.  In  both  series  the  signs  which  characterize  increas- 
ing complexity  are  the  same.  Nervous  development  and 
mental  development  pursue  exactly  parallel  lines. 

The  main  purpose  of  this  chapter  is  to  emphasize  the  fact 
that  the  higher  conscious  life  does  not  involve  any  new 
factors  or  any  different  principles  from  those  in  operation 
in  other  departments  of  Nature.  The  organism,  whether 
animal  or  plant,  is  a  little  vortex  of  matter  and  energy 
formed  here  and  there  in  the  incessant  stream  of  distribution 
and  change.  Men  think,  feel,  and  act  as  they  do  as  a 
necessary  result  of  their  physical,  and  especially  of  their 
nervous  conformation,  this  conformation  being  determined 
by  heredity,  slightly  modified  by  acquirements  subsequent  to 
birth.  Slight  though  these  modifications  intrinsically  are, 
they  are  of  first-rate  importance  relatively  to  human  conduct. 
For  in  all  essentials  the  conduct  of  men  never  varies,  if  we 
compare  it,  for  instance,  with  the  conduct  of  a  frog  or  of 
a  starfish.  Human  conduct  is  fundamentally  the  same 
all  the  world  over,  because  the  structure  of  the  human  body 
is  the  same — because  the  human  race  is  one  species  or 
protoplasmic  type.  The  differences  of  conduct  among  men 
only  appear  great  when  we  take  the  main  hereditary  basis 
for  granted,  and  fix  our  attention  wholly  on  the  divergences 
of  the  surface.  The  organism  is  a  machine,  whose  function 
is  that  of  energy -transformation.  A  stimulus  set  up  upon 
K 


130    MODERN  SCIENCE  AND  MATERIALISM 

the  surface  works  internal  changes,  which  issue  in  action. 
That  is  to  say,  energy  absorbed  from  without  is  transformed 
into  other  kinds  of  energy  according  to  the  common  laws 
of  physics  and  chemistry.  The  precise  manner  of  trans- 
formation depends  upon  the  structure  of  the  organic 
machine. 

Moreover,  the  organism  contains  within  itself  a  very 
concentrated  fund  of  energy.  As  a  consequence  of  this, 
in  higher  organisms,  all  direct  relation  is  lost  between  the 
incoming  and  outgoing  energy.  Energy  may  continue  for  a 
period  to  be  stored  up  by  anabolic  process,  much  in  excess  of 
what  leaves  the  organism.  And  then  a  very  small  external 
stimulus  may  act  like  a  spark  on  gunpowder,  and  energy  may 
be  released  with  katabolism  at  a  higher  rate  than  it  is 
absorbed.  All  this  depends  upon  organic  structure. 

Many  persons  condemn  the  mechanistic  doctrine  on 
altogether  irrelevant  grounds.  If  human  conduct  is  totally 
determined  by  structure  and  environment,  what,  they  ask, 
becomes  of  moral  responsibility  and  free-will  ?  Why  are  we 
not  fatalists  ?  To  this  there  are  two  answers.  The  first 
is,  that  we  are  searching  for  the  truth  of  the  matter, 
independently  of  its  moral  effects  upon  the  human  race.  If 
the  truths  of  physiology  are  such  as  to  undermine  moral 
responsibility,  it  might  constitute  an  argument  for  sup- 
pressing physiology,  or  preventing  the  propagation  of 
its  truths  among  mankind,  but  it  constitutes  no  sort  of 
argument  for  denying  the  truths  themselves.  If  moral 
responsibility  is  a  superstition,  the  mere  fact  that  it  is 
an  exceedingly  useful  one  does  not  make  it  any  the  less 
a  superstition. 

But  the  second  answer  is  that  the  truths  of  physiology, 
so  far  from  undermining  moral  responsibility  or  freedom 
of  will,  provide  them  with  a  far  stronger  support  than  they 
have  ever  had  before.  The  belief  that  physiological 
mechanism  results  in  fatalism  is  due  to  a  very  imperfect 
comprehension  of  the  doctrine.  Fortunately  there  is  no 


THE  FALLACY  OF  VITALISM  131 

occasion  to  argue  on  a  matter  which  can  be  settled  by  direct 
observation.  Materialism  in  history  has  never  yet  been 
associated  with  fatalism,  nor  has  any  mechanist  ever  been 
a  fatalist.  Fatalism,  on  the  other  hand,  is  characteristic 
of  the  highly  spiritualistic  religions  of  various  Eastern  races. 
Moreover,  the  Church  doctrine  of  Predestination  is  far  more 
open  to  the  charge  of  fatalism  than  is  any  theory  of 
physiology  or  logic. 

Many  are  repelled  by  the  doctrine  that  an  animal  can  be 
physically  analogous  to  a  machine;  and,  curiously  enough, 
those  objectors  are  chiefly  found  among  those  who  entertain 
the  opinion  that  animals  are  made  by  an  all-powerful  Deity. 
But  surely  if  Man  can  make  machines  of  a  simple  kind  like 
the  steam-engine  in  order  to  convert  energy,  could  not 
an  all-powerful  Deity  make  machines  of  the  immeasurably 
more  complex  kind  called  an  animal  ?  The  principle  is 
the  same,  and  that  only.  The  difference  is  one  of  com- 
plexity. Can  we  set  limits  to  the  complexity  of  a  machine 
made  by  an  all-powerful  Creator  ?  A  machine  does  not 
resemble  an  animal  more  than  a  candle-flame  resembles  the 
Sun.  We  are  dealing  only  with  an  immeasurable  compli- 
cation of  the  simple  patterns  that  can  be  appreciated  by  our 
imagination.  In  the  Universe  as  a  whole  we  dealt  with 
infinite  greatness  ;  in  the  constitution  of  matter  we  were 
confronted  with  infinite  small  ness  ;  in  conscious  life  we  find 
infinite  elaboration  and  complexity;  but  underlying  all 
these  are  the  same  unitary  principles  at  work.  There  is 
nowhere  any  suspension  of  physical  law ;  there  is  nowhere 
any  goal  or  purpose  to  which  things  are  directed  ;  there 
is  nowhere  any  spiritual  agency  to  affect  the  blind  interplay 
of  natural  forces. 


CHAPTER   V 

MATERIALISM 

IN  the  four  preceding  chapters  we  have  surveyed  the 
present  position  of  scientific  knowledge  in  so  far  as  it  is 
relevant  to  constructive  philosophy.  We  have  extracted,  as 
far  as  possible,  such  facts  and  theories  from  different  branches 
of  science  as  can  furnish  data  to  philosophy.  Philosophy  of 
necessity  is  rooted  in  science ;  but  it  does  not  follow  that  all 
the  doctrines  of  science  possess  some  philosophic  import. 
Many  of  them  are  more  or  less  isolated  truths  of  no  special 
significance,  other  than  what  appears  on  the  surface.  Many 
of  them,  on  the  contrary  (and  they  are  those  which  we  have 
endeavoured  to  present  in  the  foregoing  chapters),  possess 
a  deeper  significance  than  the  bare  facts  which  they 
enunciate.  They  are  items  in  natural  knowledge  like  the 
rest ;  but  they  are  items  which  may  be  used  as  bricks  in  the 
building  of  a  larger  edifice.  They  help  to  furnish  us  with  a 
wider  view  over  the  landscape  of  Nature ;  not,  indeed,  to 
solve  any  ultimate  mysteries — that  is  the  putative  province 
of  metaphysics  and  theology — but  to  indicate  a  few  laws  of 
wide  generality,  such  as  may  properly  be  called  philosophic. 
The  induction  of  philosophic  principles  from  scientific 
doctrines  can  at  present  only  be  carried  on  to  an  extremely 
limited  degree.  The  conclusions  that  emerge — however 
limited  they  may  be — are  the  sole  clue  that  we  can  ever  have 
to  the  mysteries  of  life  and  existence.  They  are  infinitesimal 
enough,  no  doubt,  but  beyond  them  all  is  darkness. 

To  any  individual  or  any  society  which  has  had  no 
experience  or  education,  the  world  simply  presents  a  disordered 
medley  of  objects  and  events.  The  objects  are  heterogeneous, 

132 


MATERIALISM  133 

unclassified  and  meaningless ;  the  events  are  a  clash  of  unruly 
forces,  for  which  no  cause  is  assignable  arid  no  future  con- 
sequence deducible.  At  this  stage  of  development,  mankind, 
like  any  of  the  lower  animals,  lives  exclusively  in  the  present, 
and,  in  fact,  is  unconscious  either  of  a  past  or  of  a  future.  The 
whole  mental  content,  the  whole  Universe,  for  such  a  mind  is 
comprised  in  the  objects  and  events  which  for  the  moment 
are  in  occupation  of  consciousness. 

Among  the  individuals  of  civilized  communities  this 
primitive  mental  condition  is  passed  at  quite  an  early  age. 
One  of  the  earliest  symptoms  of  the  growing  enlightenment 
is  the  child's  inquiry  how  it  came  into  the  world,  and  where 
it  wras  before  it  was  born.  Already  the  life,  limited  to  the 
present  consciousness,  has  begun  to  dissipate.  Soon  new 
problems  arise,  acquaintance  is  made  with  the  fact  of  death, 
and  the  child  begins  to  speculate  what  happens  to  it  after 
death.  As  it  grows  older,  and  gradually  comes  to  realize  the 
inevitableness  of  its  own  death,  the  question  of  its  fate  after 
death  becomes  one  of  enthralling  interest,  which  almost 
entirely  eclipses  the  problem  of  its  past  career  before  birth. 
And  so  new  problems  are  continually  opening  out  as  the 
mind  develops.  Our  lives  fill  a  span  of  a  few  years  in  the 
midst  of  infinite  time.  Our, ..world  is  a  great  spheroid  of 
matter,  set  in  the  midst  of  infinite  space.  We  can  flit  in 
imagination  from  one  star  to  another  in  a  moment  of  time. 
It  does  not  take  a  second  to  transfer  our  thoughts  from  the 
room  we  sit  in  to  the  great  nebula  in  Orion.  But  however 
vast  the  distances  we  can  thus  traverse  in  imagination,  no 
imagination  serves  to  bring  us  any  nearer  to  a  boundary  of 
space,  or  to  a  beginning  or  end  of  time. 

It  is  from  speculations  of  this  character  that  philosophy 
took  its  rise.  And  the  result  of  inquiry  has  commonly  been 
that  new  problems  rise  upon  the  intellectual  horizon  faster 
than  the  old  problems  are  solved  or  otherwise  disposed  of. 
Hence  there  is  collected  a  vast  sphere  of  inquiry  and  specu- 
lation, of  immense  human  interest,  to  which  we  give  the 


134     MODERN   SCIENCE   AND   MATERIALISM 

name  of  philosophy.  In  early  times  all  such  questions  are 
answered  .almost  as  soon  as  they  are  asked.  A  primitive 
people  cannot  brook  the  Agnostic  attitude ;  they  must  have 
an  answer,  and  there  are  no  rules  of  logic  to  limit  their 
methods ;  hence  they  leap  at  anything,  however  absurd,  that 
offers  some  escape  from  the  unpleasant  hesitation  and  con- 
fession of  ignorance  that  are  forced  upon  a  more  educated 
intellect.  Mythologies  spring  up  in  company  with  grotesque 
systems  of  physics  and  metaphysics,  which,  however  little  they 
may  have  in  common  with  truth,  and  however  far  they  may 
be  from  possibility  of  verification,  at  all  events  relieve  that  sus- 
pense which  is  so  intolerable  an  attitude  to  the  undisciplined 
mind. 

It  thus  comes  about  that  civilization  receives  from  the 
past,  not  only  an  immense  number  of  philosophical  problems, 
but  a  more  than  corresponding  number  of  solutions.  Now, 
putting  aside  the  question  as  to  whether  many  of  these 
problems  are  or  are  not  soluble,  it  is  certain  that  the  early 
solutions  presented  are  erroneous,  or  even  meaningless.  A 
first  result  of  scientific  training,  therefore,  is  the  acquisition 
of  a  position  of  Agnosticism  or  scepticism.  Just  as,  in  the 
ordinary  affairs  of  life,  the  untrained  mind  can  with  difficulty 
be  restrained  from  injudicious  meddling ;  just  as,  in  many  of 
the  more  difficult  situations  of  practical  life,  it  requires  a  far 
higher  knowledge  and  mental  calibre  to  remain  still  and  to  do 
nothing  than  to  do  something,  when  action  is  more  likely  to 
bring  evil  consequences  than  good ;  so,  in  the  philosophical 
sphere,  the  conscious  recognition  of  impotence  to  deal  with 
some  problem  implies  and  requires  a  far  higher  mental  develop- 
ment than  the  prompt  adoption  of  one  or  other  of  the 
many  solutions  commonly  proposed  from  several  sides. 
Hence  it  is  that  with  enlightenment  comes  a  great  con- 
traction of  the  sphere  of  problems  to  which  answers  are 
given.  There  is  an  ever-increasing  differentiation  between 
the  problems  of  science  and  the  problems  outside  science. 
Formerly  all  such  problems  received  solutions,  and  they  were 


MATERIALISM  135 

in  most  cases  full  of  inaccuracy  or  error.  The  purging  of 
error  is  a  difficult,  and  always  an  unpopular,  process.  Now 
the  problems  of  science  receive  solutions  which  commonly 
attain  a  high  degree  of  accuracy  and  permanence.  The 
problems  outside  science,  on  the  other  hand,  come  in  many 
cases  to  be  regarded  as  insoluble.  The  area  of  inquiry 
adopted  by  the  ancients  has  been  divided  by  the  moderns 
into  two  very  distinct  regions.  In  the  one,  answers  are 
furnished  which  greatly  surpass  those  of  the  ancients  in 
fullness  and  in  accuracy;  in  the  other,  few  answers  are 
furnished  at  all — scepticism  reigns  in  striking  contrast  to  the 
luxurious  speculations  of  the  past. 

The  majority  of  philosophers  hold  that  there  are  other 
means  to  knowledge  besides  those  of  natural  science :  they 
have  not  yet  lost  faith  in  the  methods  of  metaphysics. 
When,  however,  we  compare  the  fertility  of  science  with 
the  barrenness  of  metaphysics  during  the  last  two  or  three 
thousand  years,  we  cannot  discern  the  smallest  claim  on  the 
part  of  metaphysics  to  any  recognition  as  a  meaAs  for  the 
discovery  of  truth.  Metaphysics  is  like  a  house  built  upon 
the  sand ;  its  foundations  are  for  ever  shifting  with  every 
new  exponent  of  the  art.  Science  is  like  a  house  built  upon 
a  rock ;  so  firm  are  its  foundations  that  each  generation  of 
workers  adds  a  new  storey  to  the  edifice.  We  cannot  admit, 
therefore,  that  metaphysics  is  a  rival  method  to  science,  but 
regard  it  rather  as  a  study  of  the  same  order  and  validity 
as  theology.  Only  by  the  methods  of  science  can  knowledge 
be  attained ;  any  other  point  of  view  than  the  scientific  is 
worse  than  useless,  since  it  leads  not  to  knowledge,  but  to 
pseudo-knowledge.  Our  only  hope  of  any  real  constructive 
philosophy  lies  in  gathering  together  and  co-ordinating  the 
larger  principles  that  emerge  from  a  study  of  science. 

I  am  fully  aware  of  the  prejudice  against  any  sort  of 
constructive  efforts  that  exists  in  the  minds  of  many  who, 
like  myself,  believe  in  no  other  means  of  attaining  truth 
than  those  of  natural  science.  I  venture  to  believe,  however, 


136    MODERN  SCIENCE  AND  MATERIALISM 

that  the  position  of  extreme  Agnosticism  is  inclined  to  be 
overdone  by  a  very  natural  reaction  against  the  exaggerated 
claims  of  metaphysics  and  theology.  It  is  inferred  that, 
because  so  many  futile  inroads  on  philosophy  have  been 
made  by  these  ancient  but  discredited  methods,  therefore 
no  discussion  of  philosophical  problems  can  ever  lead  to  solid 
results.  This  question,  after  all,  depends  very  much  on  the 
definition  to  be  attached  to  the  word  philosophy.  I  shall 
not,  indeed,  attempt  to  give  it  a  formal  definition  :  the  body 
of  the  present  work  will  itself  constitute  the  best  definition  of 
what  I  mean  by  philosophy.  There  appears  to  me  no  sharp 
division  between  science  and  philosophy.  The  name  philo- 
sophical is  applicable  to  those  wide  theories  of  science,  such 
as  that  of  natural  selection,  by  which  vast  quantities  of 
isolated  facts  become  connected  together,  or  to  some  extent 
"  explained."  The  bare  collection  of  facts  which  remain 
solitary  and  meaningless  is  not  philosophy.  The  co-ordina- 
tion and  interpretation  of  those  facts  by  the  formulation  of 
general  laws  and  principles  is  philosophy.  We  may  have  a 
philosophy  of  science,  just  as  we  may  have  a  philosophy  of 
history.  In  the  case  of  history,  the  raw  material  consists 
of  bald  facts — of  dates,  events,  battles,  names  of  kings,  etc. 
— which  to  an  unintelligent  mind  is  a  mere  chronicle  of  time, 
carrying  no  information  other  than  what  is  included  in  the 
plain  recital  of  the  facts.  But  the  philosophic  historian, 
such,  for  instance,  as  Tacitus  or  Gibbon,  co-ordinates  the 
facts,  -seeks  out  causes,  draws  inferences,  and  endows  the 
whole  subject  with  life  and  fire.  They  learn  from  their 
studies  far  more  than  is  borne  upon  the  face  of  the  facts 
they  deal  with,  and  their  knowledge  of  the  past  becomes  of 
great  value  for  the  present,  if  not  for  actually  prophesying 
future  events,  at  least  for  determining  the  kind  of  results 
which  are  likely  to  flow  from  the  establishment  of  various 
kinds  of  social  institutions. 

In  just  the  same  way  the  dry  bones  of  science  are  animated 
by  an  infusion  of  the  philosophic  spirit.     It  does  not  follow 


MATERIALISM  137 

that  because  metaphysics  has  vainly  endeavoured  to  explain 
the  Universe,  therefore  every  kind  of  philosophical  theory 
must  be  false.  This  would  be  to  argue  that  because  we  do 
not  believe  in  Plato,  therefore  the  law  of  gravitation  is 
untrue.  Doubtless,  as  I  have  said,  the  matter  is  largely  one 
of  definitions.  If  by  philosophy  we  mean  an  inquiry  into 
the  origin  of  the  Universe,  then  it  should  be  severely  dis- 
carded. By  philosophy  I  mean  those  inquiries  of  the  widest 
interest,  which  can  be  approached  and  dealt  with  by  the  same 
methods  as  those  obtaining  in  natural  science.  Philosophy 
does  not  occupy  a  sphere  outside  science,  any  more  than  in 
the  case  of  history  there  is  a  separate  department  of  philo- 
sophy. In  both  cases  philosophy  is  a  method  of  treatment, 
not  a  separate  subject.  I  use  the  term  to  denote  those 
operations  which  are  carried  out  after  the  requisite  facts 
have  been  collected.  Both  in  science  and  in  history  we  must 
begin  by  the  simple  accumulation  of  facts,  and,  meanwhile, 
we  must  remain  philosophically  agnostic.  When  we  have 
got  our  raw  material  of  facts,  we  can  then  begin  to  co-ordi- 
nate and  classify  them,  that  is  to  say,  introduce  the  philo- 
sophic method.  Without  some  such  philosophic  treatment 
the  facts  remain  useless  and  uninteresting,  science  cannot 
be  brought  into  the  service  of  humanity,  nor  can  true 
knowledge  be  advanced.  No  one  would  be  interested  to  hear 
that  the  542nd  word  of  this  chapter  is  "  the."  It  is  or  may 
be  a  bald  fact,  devoid  of  philosophic  significance,  and  no 
accumulation  of  such  facts  could  ever  constitute  genuine 
knowledge.  As  in  the  arts,  and  as  in  history,  our  raw 
material  is  of  no  use  to  us  until  it  has  been  properly  worked 
up.  We  have  to  apply  the  processes  of  synthesis  and 
analysis,  which  illuminate  the  facts  brought  in  by  the 
workers,  give  them  life  and  meaning,  and  suggest  lines  of 
research  for  the  discovery  of  other  facts  in  corroboration  or 
the  reverse. 

The  main  purpose  of  the  present  work  is  to  defend  the 
doctrine  of  materialism.     It  is,  indeed,  a  materialism  infi- 


138    MODERN   SCIENCE  AND  MATERIALISM 

nitely  different  from  that  of  the  ancients,  for  it  makes 
vast  concessions  to  Agnosticism,  and  it  concedes  the  whole 
foundation  of  knowledge  to  idealism.  Yet  it  remains 
materialism ;  for  I  shall  endeavour  to  show  that  the  whole 
of  the  positive  knowledge  available  to  mankind  can  be 
embraced  within  the  limits  of  a  single  materialistic  system. 
The  outlines  of  this  system  are  not  new ;  the  main  features 
of  it,  indeed,  have  been  admittedly  associated  with  scientific 
progress  for  centuries  past.  An  age  of  science  is  necessarily 
an  age  of  materialism  ;  ours  is  a  scientific  age,  and  it  may 
be  said  with  truth  that  we  are  all  materialists  now.  The 
main  principles  which  I  shall  endeavour  to  emphasize  are 
three. 

1.  The  uniformity  of  law.  In  early  times  events  appeared 
to  be  entirely  hazardous  and  unaccountable,  and  they  still 
seem  so,  if  we  confine  attention  purely  to  the  passing  moment. 
But  as  science  advances,  there  is  disclosed  a  uniformity  in 
the  procedure  of  Nature.  When  the  conditions  at  any  one 
moment  are  precisely  identical  with  those  which  prevailed 
at  some  previous  moment,  the  results  flowing  from  them  will 
also  be  identical.  It  is  found,  for  instance,  that  a  body  of 
given  mass  attracts  some  other  body  of  given  mass  at  a 
given  distance  with  a  force  of  a  certain  strength.  It  is  found 
that  when  the  masses,  distances,  and  other  conditions  are 
precisely  repeated,  the  attraction  between  the  bodies  is 
always  exactly  the  same.  It  is  found,  further,  that  when  the 
distance  between  the  bodies  is  increased  the  force  of  their 
attraction  is  diminished  in  a  fixed  proportion,  and  this  again 
is  found  to  hold  true  at  all  distances  at  which  they  may  be 
placed.  The  force  of  their  attraction  again  varies  in  a 
different  but  still  constant  proportion  to  their  masses.  And 
hence  results  the  law  of  gravitation,  by  which  the  force  of 
attraction  can  be  precisely  estimated  from  a  knowledge  of  the 
masses  and  distances  between  any  two  bodies  whatever.  A 
uniformity  is  established  which  remains  absolute  within  the 
experience  of  Man,  and  to  an  equivalent  extent  the  haphazard 


MATERIALISM  139 

appearance  of  events  is  found  to  be  only  an  appearance. 
Innumerable  other  laws  of  a  similar  character  are  gradually 
discovered,  establishing  a  sort  of  nexus  between  every  kind 
of  event.  If  oxygen  and  hydrogen  in  the  proportion  by 
weight  of  eight  to  one  are  mixed  together,  and  an  electric 
spark  is  passed  through  them,  water  is  formed ;  and  on  every 
occasion  where  precisely  the  same  conditions  are  realized 
precisely  the  same  result  ensues.  This  truth  is  the  basis  of 
the  experimental  method.  If  from  similar  conditions  it  were 
possible  that  dissimilar  results  should  follow  on  various 
occasions,  then  experiments  would  be  useless  for  advancing 
knowledge. 

This  uniformity  of  sequence  confers  the  power  of  prophesy ; 
and  the  more  we  learn  about  the  nexus  of  natural  phenomena, 
the  greater  becomes  our  power  of  prophesying  future  events. 
Such  prophesies  are  made  and  fulfilled  at  the  present  day  in 
all  departments  of  knowledge  where  the  data  or  conditions 
are  sufficiently  few  and  simple  to  be  dealt  with  by  calculation, 
as,  for  instance,  in  many  astronomical  problems.  They  are 
made  even  when  the  data  are  numerous  and  complicated, 
though  with  much  less  accuracy.  We  can  foretell  at  what 
minute  on  what  day  an  eclipse  of  the  Sun  will  begin  to  take 
place.  We  can  equally  foretell  that  a  rise  in  the  bank-rate 
will,  under  normal  conditions,  cause  an  influx  of  gold  ;  but 
precisely  how  much  gold  we  cannot  tell.  With  a  larger 
knowledge  of  the  conditions,  we  could  arrive  at  a  closer 
approximation  to  the  amount  of  the  influx.  With  an 
absolute  knowledge  of  all  the  conditions  at  work,  we  could 
prophesy  the  exact  number  of  ounces  of  gold  that  any 
specified  rise  of  bank-rate  would  divert  into  this  country. 
Such  a  knowledge,  of  course,  is  for  ever  impossible,  since  the 
factors  concerned  are  innumerable  and  severally  minute;  to 
apply  mathematical  analysis  to  them,  even  if  they  could  all 
be  collected,  would  infinitely  transcend  our  powers.  Never- 
theless, we  shall  be  led  to  adopt  the  proposition  of  Laplace,1 

1  Essai  Philosophique  SurLes  Probability,  1819,  p.  4. 


140     MODERN   SCIENCE  AND   MATERIALISM 

to  the  effect  that  if  we  knew  the  precise  disposition  at  any 
moment  of  all  the  matter  and  energy  existing  in  the  Universe, 
and  the  direction  of  motion  of  every  moving  particle,  and  if 
we  were  armed  with  a  mathematics  of  infinite  power,  we 
should  be  able  to  prophesy  the  exact  disposition  of  all  the 
matter  and  energy  in  the  Universe  at  any  future  time.  Any 
being  who  possessed  such  powers,  and  who,  a  myriad  ages  ago, 
had  acquired  absolute  knowledge  at  some  moment  of  the 
nebula  from  which  the  solar  system  arose,  would  have  been 
able  to  prophesy  that  at  this  present  moment  there  would 
exist  a  being  identical  with  myself  who  would  be  writing  the 
words  that  are  now  flowing  from  my  pen  ;  he  would  have 
been  able  to  prophesy  that  a  little  later  other  beings, 
identical  with  my  readers,  would  be  perusing  those  words, 
and  he  would  be  aware  of  what  emotions  would  be  excited 
within  them  by  the  perusal.  In  other  words,  the  uniformity 
of  Nature  and  the  paramountcy  of  law  are  universal  and 
without  exception. 

2.  The  denial  of  teleology.  Scientific  materialism  warmly 
denies  that  there  exists  any  such  thing  as  purpose  in  the 
Universe,  or  that  events  have  any  ulterior  motive  or  goal  to 
which  they  are  striving.  It  asserts  that  all  events  are  due 
to  the  interaction  of  matter  and  motion  acting  by  blind 
necessity  in  accordance  with  those  invariable  sequences  to 
which  we  have  given  the  name  of  laws.  This  is  an  important 
bond  of  connection  between  the  materialism  of  the  ancient 
Greeks  and  that  of  modern  science.  Among  all  peoples  not 
"highly  cultivated  there  reigns  a  passionate  conviction,  not 
only  that  the  Universe  as  a  whole  is  working  out  some 
pre-determined  purpose,  but  that  every  individual  part  of  it 
subserves  some  special  need  in  the  fulfilment  of  this  purpose. 
Needless  to  say,  the  purpose  has  always  been  regarded  as 
associated  with  human  welfare.  The  Universe,  down  to  its 
smallest  parts,  is  regarded  by  primitive  superstition  as  exist- 
ing for  the  special  benefit  of  man.  To  such  extreme  lengths 
has  this  view  been  carried  that  even  Bernardin  de  Saint-Pierre, 


MATERIALISM  141 

who  only  died  last  century,  argued  that  the  reason  why 
melons  are  ribbed  is  that  they  may  be  eaten  more  easily  by 
families. 

The  reason  for  this  early  teleology  is  obvious.  We  all  of  us 
survey  the  Universe  from  the  standpoint  of  our  own  centrality. 
Subjectively  we  all  do  stand  actually  at  the  centre  of  the 
Universe.  Our  entire  experience  of  the  Universe  is  an  experi- 
ence of  it  as  it  affects  ourselves ;  for  if  it  does  not  affect 
ourselves,  we  know  of  it  only  indirectly,  and  in  primitive 
stages  we  do  not  know  of  it  at  all.  As  our  education  endows 
us  with  a  wider  outlook  and  a  wider  knowledge,  we  come  to 
see  that  the  objective  Universe  is  very  different  from  our  own 
private  subjective  Universe.  At  first  we  discover  that  we  as 
individuals  are  not  the  centre  of  the  Universe,  as  appears  to 
unconnected  experience,  but  that  we  are  merely  one  individual 
among  many  others  of  equal  status  constituting  a  nation  or 
society.  We  then  perhaps  regard  our  own  society  as  the 
centre  of  the  Universe,  as  many  primitive  peoples  do,  such, 
for  instance,  as  the  ancient  Romans  and  the  modern  Chinese. 
Or  we  may  regard  our  own  sex  as  the  purposed  product  of 
the  Universe,  as  in  many  Mohammedan  peoples,  who  hold 
that  women  have  not  souls  like  men,  and  that  they  exist 
purely  for  the  benefit  or  use  of  men,  in  the  same  way  that 
cattle  exist  in  order  to  be  eaten,  or  that  melons  are  ribbed  to 
indicate  the  proper  amount  of  one  portion. 

With  still  further  cultivation,  the  entire  human  species 
becomes  regarded  as  the  centre  and  object  of  all  events  in 
the  Universe.  This  is  the  stage  now  reached  by  the  masses 
in  modern  civilizations.  Just  as  the  existence  of  one  par- 
ticular individual  has  not  the  world-wide  or  cosmic  import- 
ance that  that  individual  is  apt  to  suppose ;  just  as  the 
existence  of  a  particular  tribe  or  society  is  not  of  the 
profound  historic  import  that  that  tribe  or  society  very 
commonly  imagines ;  so  too  the  human  species  as  a  whole 
is  far  from  being,  as  it  too  often  believes,  the  sole  object 
for  which  the  Universe  was  created,  with  all  things  in  it, 


142    MODERN  SCIENCE  AND  MATERIALISM 

great  and  small.  The  human  species  is,  indeed,  a  mere 
incident  in  the  universal  redistribution  of  matter  and 
motion ;  its  existence  has  not  the  smallest  cosmic  signifi- 
cance. Our  species  is  biologically  very  modern.  Neither 
in  numbers  nor  in  antiquity  can  it  compare  with  infinitely 
numerous  species  of  other  animals  inhabiting  the  Earth. 
The  Earth  itself  is  one  of  the  smaller  planets,  revolving 
round  a  minor  star.  The  entire  solar  system,  of  which  the 
Earth  is  so  insignificant  a  portion,  is  itself  a  system  of 
contemptible  minuteness,  set  among  other  luminaries  and 
other  systems  which  surpass  it  many  times  in  magnitude, 
in  brightness,  and  in  every  other  ascertainable  quality  that 
we  are  accustomed  to  admire. 

When  it  is  alleged  that  the  Universe  is  purposive,  it  is 
assumed  that  humanity  is  intimately  connected  with  the 
purpose.  Without  that  assumption,  none  but  the  most 
transcendental  of  philosophers  would  have  any  interest  in 
maintaining  teleology.  As  the  anthropocentric  doctrine 
falls,  therefore,  the  doctrine  of  teleology  must  fall  with  it. 
This,  at  all  events,  is  the  position  taken  up  by  scientific,  as 
indeed  by  all  materialism ;  it  is  the  position  that  I  hope 
I  shall  have  little  difficulty  in  defending  in  the  following 
pages.  Nevertheless,  however  obvious  its  truth,  we  must 
recognize  that  it  involves  a  profound  alteration  in  the 
existing  mental  point  of  view  of  the  majority  of  mankind ; 
for  most  men  have  as  yet  not  shaken  off  the  habit,  which 
all  men  necessarily  start  from,  that  they  themselves,  or  their 
family,  nation  or  kind,  are  in  fact,  as  in  appearance,  the 
very  centre  of  the  cosmos. 

3.  The  denial  of  any  form  of  existence  other  than  those 
envisaged  by  physics  and  chemistry,  that  is  to  say,  other 
than  existences  that  have  some  kind  of  palpable  material 
characteristics  and  qualities.  It  is  here  that  modern  mate- 
rialism begins  to  part  company  with  ancient  materialism, 
and  it  is  here  that  I  expect  the  main  criticisms  of  opponents 
to  be  directed.  The  modern  doctrine  stands  in  direct 


MATERIALISM  143 

opposition  to  a  belief  in  any  of  those  existences  that  are 
vaguely  classed  as  "spiritual."  To  this  category  belong 
not  only  ghosts,  gods,  souls,  et  hoc  genus  omne,  for  these 
have  long  been  rejected  from  the  beliefs  of  most  advanced 
thinkers.  The  time  has  now  come  to  include  also  in  the 
condemned  list  that  further  imaginary  entity  which  we  call 
"mind,"  "consciousness,"  etc.,  together  with  its  various  sub- 
species of  intellect,  will,  feeling,  etc.,  in  so  far  as  they  are 
supposed  to  be  independent  or  different  from  material 
existences  or  processes. 

I  beg  that  the  reader  will  not  hastily  repudiate  a  sug- 
gestion which,  until  rightly  understood,  must  appear  almost 
as  absurd  as  did  Berkeley's  original  formulation  of  idealism. 
It  seems  to  the  ordinary  observer  that  nothing  can  be  more 
remotely  and  widely  separated  than  some  so-called  "  act  of 
consciousness  "  and  a  material  object.     An  act  of  conscious- 
ness or  mental  process  is  a  thing  of  which  we  are  immedi- 
ately and  indubitably  aware :  so  much  I  admit.     But  that 
it  differs  in  any  sort  of  way  from  a  material  process,  that 
is  to  say,  from  the  ordinary  transformations  of  matter  and 
energy,   is   a   belief  which    I    very  strenuously   deny,    and 
which  I  propose  to  discuss  and  elucidate  at  length  in  my 
final    chapter.     The   proposition   which   I    here    desire   to 
advance    is   that   every   event    occurring    in    the    Universe, 
including  those  events  known  as  mental  processes,  and  all 
kinds  of  human  action  or  conduct,  are  expressible  purely  in 
terms  of  matter  and  motion.     If  we  assume  in  the  primeval 
nebula  of  the  solar  system  no  other  elementary  factors  beyofid 
those  of  matter  and  energy  or  motion,  we  can  theoretic- 
ally,  as    above    remarked,   deduce    the    existing    Universe, 
including  mind,  consciousness,  etc.,  without  the  introduction 
of  any  new  factor  whatsoever.     The  existing  Universe  and 
all  things  and  events  therein  may  be  theoretically  expressed 
in   terms    of    matter    and    energy,   undergoing   continuous 
redistribution   in    accordance    with    the    ordinary    laws   of 
physics   and   chemistry.     If  all   manifestations   within   our 


144    MODERN  SCIENCE  AND  MATERIALISM 

experience  can  be  thus  expressed,  as  has  for  long  been 
believed  by  men  of  science,  what  need  is  there  for  the 
introduction  of  any  new  entity  of  spiritual  character,  called 
mind  ?  It  has  no  part  to  play ;  it  is  impotent  in  causation. 
According  to  Huxley's  theory  it  accompanies  certain  physical 
processes  as  a  shadow,  without  any  power,  or  any  reason, 
or  any  use.  The  world,  as  Huxley  and  the  great  majority 
of  physiologists  affirm,  would  be  just  the  same  without  it. 
Now  there  is  an  ancient  logical  precept  which  retains  a 
large  validity :  entia  non  sunt  multiplicanda  prosier  necessi- 
tate™,. It  is  sometimes  referred  to  as  William  of  Occam's 
razor,  which  cuts  off  and  rejects  from  our  theories  all 
factors  or  entities  which  are  superfluous  in  guiding  us  to 
an  explanation.  "Mind"  as  a  separate  entity  is  just  such 
a  superfluity.  I  will  not  deny — indeed  I  cordially  affirm — 
that  it  is  a  direct  datum  of  experience;  but  there  is  no 
direct  datum  of  experience  to  the  effect  that  it  is  anything 
different  from  certain  cerebral  processes.  If  uneducated 
experience  seems  to  deny  the  identity,  the  denial  rests  upon 
an  inference  or  deduction  which  is  just  as  faulty  as  was 
the  denial  of  Berkeley's  theory  that  what  we  call  matter 
is  no  more  than  sense-impressions.  In  passing,  I  may  point 
out  the  difference  here  disclosed  between  modern  scientific 
materialism  and  the  crude  materialism  of  the  ancients. 
They  agree  in  declaring  the  uniformity  of  law ;  they  agree 
in  denying  the  doctrine  of  teleology ;  they  agree  that  all 
existences  are  of  a  material  character.  But  they  disagree 
in  their  treatment  of  the  alleged  spiritual  and  unseen  world. 
The  ancient  materialists  believed  to  a  certain  extent  in  an 
unseen  world  ;  they  believed  even  in  the  existence  of  souls. 
They  asserted  their  materialism  only  by  the  theory  that 
these  entities  were  material  in  character.  Democritus  con- 
ceived the  soul  as  consisting  of  smooth,  round,  material 
particles.  The  scientific  materialist  of  to-day  does  not 
believe  in  any  separate  existence  of  this  kind  whatever. 
He  regards  what  is  called  soul  or  mind  as  identical  with 


MATERIALISM  145 

certain  physical  processes  passing  in  a  material  brain,  pro- 
cesses of  which  the  ancient  Greeks  knew  nothing,  and, 
indeed,  which  are  still  entirely  unknown  to  all  who  have 
not  acquired  some  smattering  of  physiology. 

That  materialism  is  the  basis  of  all  science  is  a  proposition 
that  many,  if  not  most,  philosophers  would  readily  admit. 
That  it  is  the  basis  of  all  knowledge  is  a  more  comprehensive 
proposition,  which  the  majority  of  philosophers  would 
certainly  deny.^.  Yet  this  more  comprehensive  proposition 
follows  necessarily  from  the  first,  if  once  it  is  admitted 
that  there  can  be  no  knowledge  save  that  derived  from 
the  ordinary  methods  of  natural  science — observation  and 
experiment.  A  materialist  may,  and  indeed  must,  admit 
that  "  feeling "  or  some  "  conscious  "  state  is  the  original 
material  of  the  whole  of  our  experience,  when  analyzed  down 
to  its  extreme  depths.  He  must  further  admit  that  matter 
is  not,  like  feeling,  an  elementary  datum  of  experience,  but 
that  it  is  built  up  by  invariable  associations  of  conscious 
elements.  In  short,  matter  is  made  of  feeling,  as  Berkeley  • 
said ;  matter  is  clotted  consciousness ;  it  is  a  derivative 
of  acquired  experience,  precisely  of  the  same  order  as 
time  and  space.  It  may  be  regarded,  like  time  and  space,  as 
a  form  of  thought.  With  them  it  is_theJhundatiQB  of  j@JJ  that 
vast  body  of  associations  and  inter-relations  that  we  call 
knowledge,  and  when  more  highly  organized,  science.  I  do  not 
for  a  moment  defend  materialism  in  a  metaphysical  sense, 
as  would  be  the  case  if  I  were  to  affirm  that  matter  is  an  ulti- 
mate fact,  reducible  to  no  lower  or  more  recondite  elements. 
Far  from  it.  Idealism  holds  the  field,  but  scientific  materialism 
does  not  conflict  with  it,  as  crude  materialism  has  always  done. 
Out  of  the  raw  and  meaningless  "experiences  "  of  the  infant, 
there  gradually  evolve  a  set  of  constant  associations  which 
in  course  of  time  swell  up  and  form  the  sum -total  of  the 
individual's  knowledge.  This  set  of  associations  is  based 
upon  those  very  early  ones  in  which  sensations  of  colour, 
touch,  etc.,  are  combined  to  yield  the  generalized  idea  which 
L 


146    MODERN  SCIENCE  AND  MATERIALISM 

is  called  "  matter."  To  this  any  one  may  assent.  The 
peculiarity  of  the  materialist  is  to  affirm  that  no  new 
knowledge  can  Be  acquired  except  by  association  of  new 
experiences  with  the  great  sphere  of  associations  already 
established  on  the  basis  of  matter,  time  and  space.  There 
cannot  be  isolated  wisps  of  knowledge,  wholly  unassociated 
with  the  main  body,  any  more  than  there  can  exist  in 
an  animal  a  single  elementary  reflex-arc,  not  integrated  up 
with  the  nervous  system ;  and  the  comparison  is  far  more 
than  a  mere  analogy.  "I  must,  however,  leave  this  difficult 
subject  for  the  present. 

The  materialism  which  I  shall  advocate,  therefore,  is  centred 
round  three  salient  points :  the  uniformity  of  law,  the 
exclusion  of  purpose,  and  the  assertion  of  monism  ;  that  is  to 
May,  that  there  exists  no  kind  of  spiritual  substance  or  entity 
of  a  different  nature  from  that  of  which  matter  is  composed. 

The  first  of  these  propositions,  otherwise  called  the  Law 
of  Universal  Causation,  affirms  that  nothing  happens  without 
a  cause,  and  that  the  same  causes  under  the  same  conditions 
always  produce  the  same  effects.  In  order  to  gain  a  true 
comprehension  of  this  law,  we  have  to  define  what  we  mean 
by  "  cause "  and  "  effect,"  and  what  is  the  nature  of  the 
nexus  between  them.  The  conception  of  the  Universe 
from  which  we  start  is  that  of  a  great  system  of  matter 
and  motion  undergoing  redistribution  according  to  fixed 
sequences,  which  in  the  terminology  of  science  are  called 
laws.  The  matter  is  constantly  undergoing  transforma- 
tion from  one  of  its  forms  into  another,  and  the  energy 
is  redistributed  and  transformed  in  a  corresponding  manner. 
From  this  primary  conception  alone,  we  are  able  to 
derive  a  precise  definition  of  what  is  meant  by  cause, 
a  problem  which  is  almost  insuperable  from  any  other 
standpoint.  Mill  defined  one  event  as  being  the  cause  of 
another  when  the  first  event  is  found  invariably  in  experience 
to  be  followed  by  the  second.  In  cause  and  effect  he  saw 
nothing  further  than  an  invariable  sequence.  His  view  was 


MATERIALISM  147 

at  once  demolished  when  he  was  asked  whether  he  considered 
that  day  was  the  cause  of  night,  for  this  also  is  a  sequence 
invariable  in  our  experience.     But  if  we  apply  analysis,  the 
difficulty  vanishes.     If  we  regard  an  event  as  a  momentary 
phase  in  the  redistribution  of  matter  and  motion,  then  the 
cause  of  the  event  is  found  in  the  immediately  preceding 
state  of  distribution  of  that  same  matter  and  motion.     Let 
us  ask,  for  instance,  what  is  the  cause  of  the  sudden  appearance 
of  a  new  fixed  star  in  the  heavens.     Supposing  that  there 
were  previously   two  extinct   suns  moving  rapidly  towards 
each  other  and  coming  into  collision,  we  should  be  making 
a   statement    of  events   which    would   be   recognized   as   a 
possibly    true    "  cause."      The    second    event,    or    "  effect," 
is  represented  exclusively  in  terms  of  matter  and  motion  by 
the  idea  of  two  coalesced  and  volatilized  bodies  giving  rise 
to  vast   quantities   of  heat  and   light.     And   the  cause   is 
given   merely  by  stating  the  previous  distribution  of  that 
matter  and  energy  which  is  concerned  in   the  production 
of  the  event.     The  matter  concerned  in  the  event  consisted 
of  two   solid    bodies   at    a    rapidly    diminishing    distance 
from  one  another.     The  energy  consisted  of  half  the  product 
of    their   momentum    and   velocity.     By   the   collision   the 
matter    contained     in    the    solid    bodies    underwent    that 
redistribution  involved  in  passing  into  a  gaseous  state,  with 
the   decomposition    of  many   of  its    molecules,  that   is   to 
say,   with  a  rearrangement  or  redistribution  of  its  atoms. 
The  energy  of  motion   previously   contained   in   the   solid 
bodies  underwent  at  the  same  time  a  transformation  into 
heat  and  light.     The  sudden  light,  therefore,  is  explained,  or 
derives  its  cause,  merely  by  furnishing  a  statement  of  the 
previous  distribution  of  the  matter  and  energy  concerned 
in  its  production. 

Let  me  now  take  a  slightly  more  complex  instance,  that, 
namely,  of  a  specific  bacillus  as  the  cause  of  tuberculosis. 
What  is  the  cause  of  tuberculosis  ?  The  disease  is  charac- 
terized by  lesions  of  a  specific  type,  which  may  occur  in  very 


148    MODERN  SCIENCE  AND  MATERIALISM 

various  parts  of  the  body.  The  effect,  therefore,  or  the 
tuberculous  condition,  may  be  analyzed  into  a  particular 
arrangement  of  matter  and  energy.  The  arrangement,  indeed, 
is  very  similar  to  that  which  prevails  in,  and  constitutes,  a 
healthy  organism  ;  but  here  and  there  the  matter  and  energy 
are  somewhat  differently  located,  so  as  to  constitute  what  is 
called  a  tuberculous  organism. 

Before  infection,  the  matter  and  energy  of  the  organism 
were  normally  distributed.  At  the  moment  of  infection 
there  is  an  addition  of  a  minute  quantity  of  other  matter 
and  energy  specifically  distributed  into  a  number  of  little 
bodies,  which  we  call  bacilli ;  and  their  matter  and  energy, 
combined  with  the  matter  and  energy  of  the  healthy  organism, 
undergo  further  redistribution,  resulting  ultimately  in  that 
new  arrangement  which  is  characteristic  of  the  disease.  All 
this  works  by  inevitable  laws,  just  those  same  laws  which 
control  the  unceasing  redistribution  of  matter  and  motion  in 
every  part  of  the  Universe.  The  cause  of  any  phenomenon 
is  found  when  we  have  described  the  antecedent  state  of 
distribution  of  the  matter  and  energy  which  are  combined  to 
constitute  that  phenomenon. 

It  happens,  however,  that  in  practical  life  we  are  commonly 
interested  only  in  one  element  out  of  the  numerous  con- 
stituent  parts  that  go  to  make  up  a  phenomenon.  From  the 
objective  point  of  view  this  element  is  very  often  extremely 
insignificant,  yet  we  confine  the  appellation  of  cause  to  it 
alone.  In  the  example  above  cited,  the  objective  or  absolute 
cause  of  a  tubercular  lung  is  furnished  only  by  an  account  of 
the  origin  or  previous  state  of  distribution  of  the  matter  and 
energy  constituting  the  lung,  as  well  as  of  that  constituting 
the  bacilli.  But  we  are  in  the  habit  of  taking  the  lung  for 
granted,  and  referring  to  the  bacilli  as  the  cause  of  the 
disease.  The  reason  of  this  is,  that  the  matter  and  energy 
of  the  healthy  lung  undergo  transformation  normally  in  a 
uniform  and  regular  manner:  the  organ  undergoes  what 
is  called  a  healthy  metabolism.  Matter  and  energy  are 


MATERIALISM  149 

unceasingly  being  introduced  from  without,  to  take  the  place 
of  that  used  up.  We  are  only  interested  in  the  breach  of 
that  uniformity,  and  the  assumption  of  a  new  kind  of 
distribution.  Although,  therefore,  the  unceasing  supply  of 
abundance  of  new  matter  and  new  energy  is  as  essential  to 
the  continued  existence  of  a  diseased  lung  as  of  a  healthy 
lung,  and  although  this  abundance  is  objectively  the  pre- 
dominant factor  in  the  production  of  a  tuberculous  lung, 
yet  we  do  not  speak  of  it  as  the  cause  of  the  tuber- 
culous lung,  because  we  take  it  for  granted,  and  concentrate 
our  interest  on  the  new  and  unusual  factor.  From  other 
points  of  view,  we  might  take  just  the  same  facts,  originating 
in  just  the  same  way,  and  yet  assign  equally  correctly  another 
quite  different,  though,  of  course,  not  conflicting,  cause,  simply 
because  our  interest  is  differently  orientated.  Suppose,  for 
instance,  that  we  knew  nothing  of  men  or  any  animals,  but 
were  entirely  wrapped  in  the  lives  and  history  of  bacilli.  We 
may  be  watching  a  little  colony  of  bacilli  which  have,  for 
many  of  their  generations,  led  an  uneventful  or  somewhat 
precarious  existence,  perhaps  in  milk  or  dried  up  in  dust,  etc. 
Our  attention  being  fixed  exclusively  on  them,  we  may  be 
startled  to  find  that  the  colony  suddenly  becomes  inexplicably 
prosperous.  The  bacilli  become  fat  and  healthy,  they 
reproduce  in  enormous  numbers,  having  by  chance  become 
transferred  to  a  favourable  environment,  viz.  a  susceptible 
lung.  The  state  of  affairs  is  that  which  has  already  been 
described — a  lung  swarming  with  bacilli.  What  is  the  cause 
of  this  state  of  affairs?  Fixing  our  interest  now  on  the 
sudden  prosperity  of  the  bacilli,  we  must  assign  as  a  cause 
the  favourable  nutritive  condition  supplied  by  the  lung. 
From  the  point  of  view  of  the  bacilli,  that  particular  distri- 
bution of  matter  and  energy  which  we  called  a  tubercular 
lung,  is  due  to  the  continued  supply  of  nutritive  material 
through  the  blood  of  the  infected  organism.  To  the  man, 
the  cause  of  the  phenomenon  in  question  is  the  supply  of 
bacilli  to  the  lung.  To  the  bacilli,  the  cause  of  the  pheno- 


150    MODERN   SCIENCE  AND  MATERIALISM 

menon  is  the  supply  of  a  succulent  lung.  Both  are  true  and 
essential  causes ;  yet  we  only  call  by  the  name  of  cause  the 
particular  factor,  out  of  innumerable  others,  in  which  we 
happen  to  be  interested.  All  the  others  we  name  "  con- 
ditions." In  that  particular  collocation  of  matter  and  energy 
known  as  a  lung  swarming  with  bacilli,  the  man  takes  the 
lung  with  its  metabolic  processes  for  granted,  and  ascribes 
the  cause  of  the  phenomenon  to  the  invasion  of  foreign  bacilli ; 
the  bacilli  take  themselves  for  granted,  and  ascribe  the  cause 
of  the  phenomenon  to  the  food  supply  constantly  furnished 
to  the  lung. 

The  notion  of  cause  has,  therefore,  both  an  objective  and 
a  subjective  element.  Objectively,  the  cause  of  any  pheno- 
menon is  the  preceding  state  of  distribution  of  the  matter 
and  energy  concerned  in  that  phenomenon.  From  this  point 
of  view,  it  is  plain  that  the  efficient  cause  of  the  existing 
state  of  the  Universe  at  any  one  moment  is  its  state  at  the 
moment  immediately  preceding.  Subjectively,  we  are  in- 
terested, however,  only  in  the  evolution  of  some  part  of  the 
component  matter  and  energy,  and  we  are  in  the  habit  of 
conferring  the  name  of  cause  only  on  that  particular  factor  in 
the  evolution  that  happens  to  interest  us,  while  designating 
the  other  factors  conditions. 

The  above  definition  of  cause  at  once  clears  up  the  problem 
of  the  difference  between  "  how  "  and  "  why."  Many  men  of 
science,  following  Mach  and  Karl  Pearson,  have  affirmed  that 
science  can  never  explain  more  than  "  how  "  events  occur :  it 
can  never  touch  the  problem  of  "  why  "  they  occur.  On  this 
second  point  humanity  must  always  rest  ignorant.  They 
have  thus  set  up  a  deep  and  fundamental  distinction  between 
"  how  "  and  "  why  "  which  a  very  moderate  amount  of  analysis 
suffices  altogether  to  dispel.  I  must  ask  the  reader  once 
more  to  visualize  the  Universe  as  consisting  of  a  fixed  sum  of 
matter  and  energy  undergoing  redistribution.  Consider  some 
momentary  and  circumscribed  phase  of  that  evolution,  which 
in  ordinary  language  is  called  an  event,  and  let  us  see  how 


MATERIALISM  151 

we  should  answer  the  two  questions  "  how  "  and  "  why  "  this 
event  comes  about.  Clearly  we  describe  "how"  it  comes 
about,  when  we  render  a  complete  statement  of  the  immediately 
preceding  history  of  all  the  matter  and  energy  engaged  in  it. 
"  How "  corresponds  to  the  purely  objective  definition  of 
cause  given  above.  Now  let  us  ask  "  why  "  the  event  occurs. 
The  answer  is  given  by  naming  the  immediately  preceding 
history,  not  of  all  the  matter  and  motion  engaged,  but  of 
that  part  of  it  in  which  we  /happen  to  be  interested.  "  Why  " 
corresponds  to  that  final  definition  of  cause,  offered  above, 
in  which  both  objective  and  subjective  elements  are  included. 
In  fact,  "  why "  is  simply  a  limited  "  how " ;  it  covers  less 
ground ;  it  demands  the  history,  not  of  the  whole  of  the 
matter  and  energy  engaged  in  the  event,  but  only  of  a 
particular  section  of  it  which  happens  to  arouse  special 
interest. 

It  follows  from  the  above  that,  whereas  to  the  question 
"  how  "  an  event  takes  place  there  can  be  but  one  complete 
answer,  to  the  question  "  why "  it  takes  place  there  may  be 
many  answers,  and  all  equally  true.  For,  in  order  to  give  a 
complete  answer  to  "  how,"  we  have  to  describe  the  preceding 
history  of  the  entire  sum  of  the  matter  and  energy  involved  ; 
whereas  in  order  to  give  a  complete  answer  to  "  why,"  we 
only  have  to  describe  4the  preceding  history  of  one  selected 
element  in  the  sum  of  matter  and  motion,  and  we  may  choose 
at  random  many  elements,  describing  one  after  another,  to 
satisfy  the  interest  of  the  inquirer,  thus  offering  a  number 
of  true,  though  different,  answers  to  the  same  question.  To 
answer  the  question  "how,"  we  must  describe  all  the  con- 
ditions which  led  up  to  the  event.  To  answer  the  question 
"  why,"  we  name  one  of  these  conditions.  This  one  condition, 
in  which  special  interest  happens  to  be  taken,  is  then  called 
"  cause."  With  a  different  interest,  we  should  have  selected 
some  other  of  the  conditions,  and  this  one  would  then  be 
referred  to  as  the  cause.  A  few  instances  will  make  the 
matter  clear. 


152     MODERN   SCIENCE  AND   MATERIALISM 

Suppose  that  a  locomotive  engine  linked  up  to  a  train  is 
standing  at  a  railway  station,  and  that  it  suddenly  begins  to 
move  off.  Suppose  that  the  question  is  asked  "  why  "  it  has 
moved.  A  great  variety  of  answers,  all  equally  true,  might 
be  given,  and  if  we  did  not  know  the  special  interest  of  the 
inquirer,  we  should  be  altogether  at  a  loss  how  to  answer 
him.  We  may  reply  that  it  moved  off  because  it  was  timed 
to  go  at  that  hour,  or  because  the  guard  waved  his  flag,  or 
because  the  last  passenger  had  just  got  in,  or  because  the 
signal  had  gone  down,  or  because  the  engine-driver  pulled  a 
lever,  or  because  a  sudden  pressure  within  the  cylinder  had 
forced  forward  the  piston,  or  because  the  friction  between  the 
wheels  and  the  lines  exceeded  the  inertia  to  be  overcome,  or 
because  some  fault  in  the  machinery  which  had  hitherto 
prevented  its  moving  had  at  length  been  remedied.  Similarly, 
when  the  train  stops  at  the  next  station,  we  may  analyze  the 
question  "  why  "  it  stops.  We  may  reply,  to  enable  passengers 
to  get  out,  or  because  the  engine-driver  pulled  a  lever,  etc., 
etc.  And  in  .neither  case  should  we  know  which  of  the 
numerous  possible  answers  to  give,  unless  we  were  acquainted 
with  the  motives  of  the  questioner.  Each  of  these  answers 
names  one  of  the  antecedent  conditions  to  the  motion  of 
the  train,  and  we  cannot  know  which  particular  antecedent 
condition  will  satisfy  the  question  "why"  unless  we  know 
something  about  the  purpose  with  which  the  questioner  is 
animated.  If  we  had  no  such  knowledge,  it  would  be  necessary, 
to  cover  all  possibilities,  to  give  a  recital  of  the  entire  sum  of 
antecedent  conditions,  and  these  would  speedily  be  found  to 
throw  roots  far  back  into  the  past,  and  to  multiply  further 
the  more  we  followed  them,  exemplifying  the  truth  that  all 
things  in  the  Universe  are  bound  together  by  an  indissoluble 
nexus,  and  that  every  event  is  the  product,  not  of  one  or  two 
single  causes,  but  of  the  general  distribution  of  matter  and 
energy  throughout  the  Universe  at  preceding  periods  of  time. 

The  subject  seems  so  important  that  I  venture  to  cite  one 
further  example.  Suppose  the  question  asked  is,  "  Why  is 


MATERIALISM  153 

the  moon  full  to-night  ?  "  a  great  variety  of  true  answers  may 
be  offered,  when  we  are  ignorant  of  the  questioner's  special 
interest  in  the  matter.  The  moon  is  full  because  it  is  placed 
on  the  opposite  side  of  the  Earth  from  the  Sun  ;  because  it 
has  a  surface  which  reflects  light ;  because  a  month  has  elapsed 
since  last  full  moon ;  because  it  is  a  little  out  of  the  direct 
straight  line  with  the  Sun  and  Earth ;  because  the  Sun  is 
shining  upon  that  half  of  its  surface  turned  towards  the  Earth  ; 
because  rays  of  light  can  traverse  space,  eta,  etc.  Our 
answer  to  a  child  would  be  different  from  our  answer  to  an 
astronomer;  for  the  former  would  be  interested  in  different 
features  of  the  process  from  the  latter.  But  in  order  to 
furnish  a  comprehensive  answer  to  the  question  how  or  by 
what  process  the  full  moon  occurs,  all  these  factors  one  after 
another  would  have  to  be  enumerated.  The  "  why  "  of  phe- 
nomena is  no  more  than  a  special  case  of  the  "  how  "  ;  and  all 
questions  "  why  "  certain  phenomena  occur  are  answered,  if  at 
all,  only  by  relating  how  they  occur ;  nor  can  they  be  answered 
in  any  other  way ;  nor  has  the  interrogative  "  why  "  any  other 
significance  that  is  conceivable  to  mankind.  In  explaining 
why  some  phenomenon  occurs,  we  merely  have  to  exercise  an 
eclectic  discrimination  in  deciding  which  of  the  numerous 
factors  concerned  in  the  process  is  most  likely  to  satisfy  the 
curiosity  of  the  inquirer.  And  all  those  factors,  under 
analysis,  may  be  resolved  into  a  graphical  or  historical  account 
of  the  changes  undergone  from  moment  to  moment  by  the 
matter  and  energy  engaged  in  the  production  of  the 
phenomenon. 

Not  only  is  there  no  transcendental  difference  between 
how  and  why,  as  Professor  Karl  Pearson  imagines,  but,  in 
the  loose  and  imperfect  language  of  ordinary  life,  their 
meanings  insensibly  grade  into  one  another,  and  they  may 
even  be  used  indiscriminately.  The  questions  how  he  got 
tuberculosis  and  why  he  got  tuberculosis  are  very  slightly,  if 
at  all,  different.  In  other  cases  the  difference  is  greater,  as, 
for  instance,  in  the  questions  how  he  travelled  up  to  London, 


154    MODERN  SCIENCE  AND  MATERIALISM 

and  why  he  travelled  up  to  London.  The  first  question 
would  be  understood  to  refer  to  the  more  obvious  and 
palpable  redistributions  of  matter  concerned  in  the  process, 
and  would  be  sufficiently  answered  by  replying  that  he 
travelled  up  in  a  train.  The  second  question,  why  he 
travelled,  refers  to  his  motive ;  that  is  to  say,  to  one  special 
factor  antecedent  to  the  process  of  travelling,  a  factor  to 
which  particular  interest  attaches. 

And  this  leads  me  to  the  second  problem  which  I  have 
here  to  deal  with,  the  problem  of  teleology.  I  have  hitherto 
endeavoured  to  represent  the  notion  of  cause  and  effect  in 
purely  materialistic  terms,  to  the  exclusion  of  all  meta- 
physical transcendentalism  ;  to  state  the  relation  of  cause 
and  effect  in  terms  of  the  redistribution  of  matter  and 
motion.  I  now  have  to  perform  the  same  task  for  the 
conception  of  purpose,  and  more  particularly  of  human 
purpose,  in  order  to  show  how  purposiveness  may  be 
translated  into  purely  materialistic  and  mechanical  terms ; 
that  is  to  say,  how  it,  too,  may  be  expressed  as  a  phase  of  the 
normal  process  of  redistribution  of  matter  and  motion  under 
fixed  and  invariable  laws. 

At  the  outset  of  this  inquiry,  we  have  to  notice  that  the 
word  purpose  is  involved  in  the  same  vagueness  of  significance 
that  attends  almost  all  words  used  in  popular  speech.  In 
general  a  word  in  popular  use  has  to  be  defined  and  limited 
to  some  precise  meaning  before  it  is  fit  for  employment  in  a 
philosophical  discussion.  In  the  present  case  the  word  is 
commonly  employed  in  at  least  two  meanings,  which  differ 
greatly  from  each  other ;  and  this  duality  of  meaning  leads 
to  a  duality  in  the  derivative  conceptions  of  "teleology," 
"  finalism,"  "  end,""  etc.,  which  has  not  infrequently  given  rise 
to  confusion  and  error.  The  two  significations  may  be 
roughly  grouped  as  intelligent  purposiveness  and  unin- 
telligent purposiveness,  and  the  reduction  of  each  of  these 
to  mechanistic  terms  involves  two  different  lines  of  analysis. 
I  shall  deal  first  with  unintelligent  purposiveness. 


MATERIALISM  155 

In  this  case,  the  word  is  usually  applied  to  a  certain  kind 
of  organic  reactions  that  bear  an  obvious  relation  to  the 
requirements  of  the  reacting  organism.  An  Amoeba  in  the 
water  throws  out  pseudopodia  at  random  in  all  directions. 
When  one  of  these  pseudopodia  comes  into  contact  with 
some  substance  suitable  for  food,  the  protoplasm  streams 
round  and  encloses  the  particle,  which  is  thus  incorporated 
in  the  body  of  the  Amoeba  and  there  digested.  The  reaction 
is  purposive  in  the  sense  that  a  somewhat  complicated  series 
of  movements  is  carried  out,  which  leads  to  the  preservation 
of  the  active  organism. 

In  just  the  same  way,  when  we  ascend  the  animal  scale, 
the  sea-anemone  spreads  its  tentacles  at  large  under  the 
surface  of  the  water.  On  contact  with  any  substance  suitable 
for  food  the  tentacles  contract  around  the  substance  and 
draw  it  into  the  interior  of  the  sea-anemone.  This  action 
is  similarly  purposive  in  that  it  procures  the  continued 
existence  of  the  animal.  In  all  animals  the  common  move- 
ments and  reactions  are  predominantly  of  this  purposive 
type.  If  an  object  suddenly  appears  close  to  our  eyes,  we 
involuntarily  close  them  for  an  instant,  and  this  reaction 
is  obviously  purposive,  as  directed  towards  the  protection 
of  the  eyes. 

All  these  instinctive  actions  are  purposive  in  character, 
yet  equally,  without  doubt,  they  are  all  of  the  nature  of 
reflex  action,  working  blindly  and  inevitably  to  their  con- 
clusion. On  contact  with  the  tentacle  of  a  sea-anemone, 
the  stimulus  thus  applied  to  that  tentacle  sets  up  by  entirely 
mechanical  procedure  organic  processes  which  necessarily 
result  in  the  observed  contractions.  '  Similarly,  in  the  case 
of  the  human  being,  the  sudden  appearance  of  a  near  object 
causes  an  impulse  to  be  conveyed  down  the  optic  nerve, 
which  immediately  and  mechanically  propagates  its  effect 
to  the  efferent  nerves  which  lead  to  the  muscles  that  close 
the  eyelids.  The  same  kind  of  reaction  is  characteristic  of 
the  functions  in  plants.  The  turning  of  flowers  towards  the 


156    MODERN  SCIENCE  AND  MATERIALISM 

light,  and  all  the  processes  of  absorption,  transpiration,  etc., 
are,  on  the  one  hand,  subservient  to  the  life  and  prosperity 
of  the  plant,  while,  on  the  other  hand,  they  are  blind 
mechanical  reactions  to  stimuli. 

Seeing  that  a  single  action  may  thus  be  at  the  same  time 
both  purposive  and  mechanical,  it  is  plain  that  there  can 
be  no  antithesis  between  the  two ;  but  that  the  difference 
between  purpose  and  blind  mechanism  arises  simply  from  our 
point  of  view,  and  not  from  any  difference  of  objective 
character.  Purposive  reactions  are  not  different  from 
mechanical  reactions,  but  they_ar<?_meclianical  reactions  of 
a  certain  kind.  Not  all  mechanical  reactions  are  purposive, 
but  all  purposive  reactions  are  mechanical ;  and  it  remains 
to  determine  ivhat  mechanical  actions  may  be  correctly 
described  as  purposive,  and  what  are  simply  blind  and 
meaningless. 

The  distinction  is  entirely  one  of  convention.  I  have 
represented  all  events  in  the  light  of  a  redistribution  of 
matter  and  energy  under  fixed  mechanical  laws.  Certain 
particular  phases  in  this  redistribution,  certain  particular 
collocations  of  the  evolving  matter  and  energy,  happen  to 
possess  for  us  a  very  special  interest,  and  we  watch  with 
peculiar  attention  the  material  developments  and  antecedents 
which  give  rise  to  those  particular  collocations  that  concern 
us.  Of  such  collocations,  the  most  enthralling  is  the  main- 
tenance of  that  moving  equilibrium  which  we  call  the  life  of 
an  organism.  This  equilibrium  is  due  to  a  succession  of 
stimuli  from  without,  met  by  "  adapted "  reactions  .on  the 
part  of  the  organism ;  and  it  is  to  that  particular  item  of 
the  universal  mechanism  called  an  adapted  organic  reaction, 
that  we  apply  the  name  of  purpose. 

The  material  origin  of  all  purposive  reactions  would  be 
adequately  explained  by  the  theory  of  Natural  Selection. 
We  must  suppose  that,  at  the  origin  of  life,  the  primeval 
little  speck  of  organic  matter  would  respond  in  any 
haphazard  kind  of  way  to  the  stimuli  affecting  it  from 


MATERIALISM  157 

without.  These  organisms  or  pre-organisms  would  in  every 
case  give  a  blind  response,  due  to  the  chemical  or  material 
constitution  of  their  protoplasm.  By  the  ordinary  laws  of 
chance,  the  vast  majority  of  these  reactions  would  not  be 
such  as  to  promote  the  continuance  of  life,  and  in  many  cases 
would  be  such  as  immediately  to  destroy  life.  But  again, 
by  the  ordinary  laws  of  chance,  it  would  happen  in  some 
cases  that  the  response  to  external  stimuli  would  be  such  as 
in  some  way  or  other  to  favour  the  continuance  of  life. 
Pre-organisms,  the  chemical  constitution  of  whose  protoplasm 
was  of  this  type,  would  flourish  and  be  perpetuated,  while 
all  other  types  of  incipient  life  would  be  extinguished.  The 
reactions  of  the  surviving  pre-organisms  are  what  we  should 
call  "purposive."  In  this  sense,  therefore,  we  mean  by 
purpose  those  reactions  of  organic  matter  which  happen 
to  promote  the  continued  existence  of  that  organic  matter. 
By  the  mechanical  process  of  Natural  Selectipn^  all  varieties 
of  organic  matter  that  respond  unpurposivelyr-that  is,  whose 
responses  do  not  happen  to  promote  their  continued  exist- 
ence— perish,  with  the  result  that  either  the  whole  or  the 
larger  part  of  every  animal's  activities  are  purposive  in 
character.  At  first,  therefore,  Natural  Selection  is  the 
great  teleologies!  agent.  The  net  result  of  this  analysis 
is  that  purpose  is  a  name  given  to  certain  material 
phenomena  which  fulfil  some  arbitrarily  chosen  condition, 
and  withheld  from  all  other  material  phenomena  which  do 
not  fulfil  that  condition.  The  condition  usually  taken  in 
simple  cases  is  the  maintenance  of  life,  and  among  the 
factors  in  this  maintenance  of  life  are  commonly  selected 
those  which  involve  organic  activity.  All  such  organic 
activity  is  then  said  to  be  purposive. 

The  point  specially  to  be  noticed  is  that  purpose  is  purely 
arbitrary  and  subjective ;  it  corresponds  to  nothing  in  outer 
nature,  nor  are  purposive  acts  in  any  way  objectively 
different  from  random  acts.  By  selecting  a  new  set  of 
conditions  to  be  satisfied,  or  a  new  standard,  it  is  possible 


158    MODERN  SCIENCE  AND  MATERIALISM 

to  represent  any  kind  of  mechanical  event  as  being  purposive. 
Supposing,  for  instance,  that  the  condition  to  be  fulfilled 
was  that  the  planets  of  our  solar  system  should  revolve 
round  the  Sun  in  the  orbits  that  they  actually  do  ;  supposing 
that  we  had  a  great  personal  interest  in  their  doing  so,  and 
anxiously  watched  all  material  developments  in  the  primeval 
nebula  which  appeared  to  lead  to  such  a  consummation ; 
supposing  that  we  can  transfer  ourselves  to  this  cosmic  point 
of  view,  we  might  then  rightly  affirm  that  gravitation  is 
purposive,  just  as  we  now  affirm  that  Natural  Selection  is 
purposive.  The  one  leads  to  the  moving  equilibrium  of  the 
solar  system,  the  other  leads  to  the  moving  equilibrium  of 
a  living  organism.  Extinguish  gravitation,  so  that  the 
planets  move  at  hazard,  and  the  solar  system  will  not 
survive.  Extinguish  Natural  Selection,  so  that  organisms 
react  at  hazard,  and  those  organisms  will  not  survive.  The 
parallel  is  complete ;  and  there  is  no  more  a  priori  objection 
to  calling  the  movements  of  the  planets  purposive  than 
there  is  to  calling  the  movements  of  animals  purposive. 
The  former  are  "  adapted  "  to  the  continued  maintenance  of 
the  solar  system,  the  latter  to  the  continued  maintenance 
of  vital  manifestations.  If  we  do  not  call  the  cosmic 
manifestations  purposive,  but  do  call  vital  manifestations 
purposive,  it  is  because  we  are  intensely  interested  in  the 
latter,  and  but  slightly  interested  in  the  former.  The 
continuance  of  life,  the  satisfaction  of  needs,  etc.,  are 
conditions  that  appear  to  us  so  important  as  to  demand 
a  special  name  for  the  most  prominent  group  of  factors  con- 
cerned in  them  ;  whereas  the  continuance  of  the  solar  system, 
and  the  unfailing  adherence  of  the  planets  to  their  present 
orbits,  is  not  a  subject  of  such  overweening  importance,  or 
of  such  unceasing  allusion  in  common  life,  as  to  require  the 
establishment  of  a  special  name.  A  purposive  movement, 
therefore,  is  an  ordinary  case  of  the  redistribution  of  matter 
and  energy.  The  name  is  used  in  those  cases  where  the 
matter  and  energy  are  knotted  up  into  that  structure  which 


MATERIALISM  159 

we  call  a  living  organism,  and  is  applied  to  such  activities  of 
the  organism  as  conduce  to  its  own  continued  existence. 

I  now  come  to  the  second  class  of  activities  to  which  the 
name  of  purpose  is  applied,  that  is  to  say,  cases  of  activity 
which  bear  reference  to  an  end  consciously  and  intelligently 
foreseen,  such  as  the  acts  inspired  by  the  conscious  will  in 
human  beings.  These  activities  are  commonly  regarded  as 
being  in  a  higher  degree  teleological  than  the  unintelligent 
reactions  hitherto  considered ;  and  in  many  uses  of  the  word 
"purpose,"  reference  is  intended  exclusively  to  these  intelli- 
gent anticipations  of  future  events,  and  to  the  activities 
carried  out  in  consequence  of  such  anticipations.  In  this 
sense  purpose  is  allied  to  will,  and  purposive  actions  are 
more  or  less  synonymous  with  voluntary  actions.  The 
question  before  us,  therefore,  is  whether  the  will  can  be 
comprised  in  the  materialistic  scheme  which  governs  all 
other  natural  phenomena,  or  whether  it  is  something  out- 
side and  independent,  knowing  no  laws,  and  therefore  not 
amenable  to  scientific  discussion.  And  this  question,  again, 
is  nothing  more  than  the  problem  of  free-will  and  deter- 
minism ;  of  vitalism  and  mechanism ;  of  spiritualism  and 
materialism  ;  according  to  the  standpoint  from  which  we 
approach  it. 

The  exclusion  of  the  will  from  materialistic  laws  is  refuted 
by  considerations  of  every  kind,  and  refuted  with  equal 
facility  from  many  different  points  of  view :  from  biology, 
from  physiology,  from  psychology,  and  even  from  logic  alone. 
Any  one  of  these  sciences  can  furnish  overwhelming  refutation 
of  the  hypothesis  of  the  independence  of  the  will,  a  hypothesis 
which  never  could  have  obtained  any  attention  from 
philosophers  were  it  not  that  it  harmonizes  so  well  with  the 
ignorant  prejudices  and  superstitions  of  the  multitude,  and 
thus,  being  refuted  time  after  time,  was  constantly  pressed 
anew  on  their  attention. 

We  noted  in  Chapter  IV  that  there  is  no  qualitative 
difference  between  the  simpler  reflex  action  and  the  highest 


160    MODERN  SCIENCE  AND  MATERIALISM 

or  most  complicated  reactions  that  the  developed  nervous 
system  is  capable  of  evincing.  In  the  lowest  animals,  the 
nervous  system  is  adapted  simply  for  conveying  impulses 
from  the  outer  surface  to  some  nerve-centre,  whence  proceeds 
a  new  impulse  along  another  nerve  back  to  the  periphery, 
causing  a  contraction  or  some  other  movement.  The 
whole  procedure  is  purely  mechanical.  Now  the  most 
developed  known  nervous  system  arises  by  evolution  in 
gradual  stages  from  this  most  elementary  form,  and  the 
mode  of  development  consists  in  the  compounding  of  reflex 
action.  From  the  simple  reflex-arc  arise  multitudinous 
other  reflex-arcs,  integrated  together  into  one  great  nervous 
system.  Instead  of  one  nerve  running  from  periphery  to 
centre,  many  nerves  run ;  a  corresponding  multiplication 
occurs  in  the  outgoing  nerves.  The  centre  likewise  increases 
beyond  recognition  in  elaboration  and  complexity.  It  is 
broken  up  into  a  number  of  constituent  parts,  themselves 
connected  by  bundles  of  nerve-fibres,  and  higher  centres 
grow  up,  which  receive  impulses  from  the  lower  centres,  and 
send  back  others.  But  the  simple  reflex-arc  remains  the 
unit  of  functional  activity  and  of  structural  form.  However 
infinite  the  complication  of  the  developed  system,  it  is  still 
based  on  the  simple  reflex-arc,  and,  indeed,  consists  of  in- 
numerable reflex-arcs  compounded  together  in  every  variety. 
The  reflex-arc  is  mechanical  in  function  ;  hence  the  developed 
nervous  system  is  mechanical  in  function.  Nowhere  is  there 
any  break  in  development,  at  which  we  might  suppose  that 
a  new  and  non-mechanical  factor  makes  its  appearance. 

The  relation  between  the  highly  compounded  nervous 
system  of  a  man  to  the  elementary  reflex-arc  corresponds 
to  the  relation  between  the  intelligent  purposiveness  now 
under  discussion  and  the  unintelligent  purposiveness  analyzed 
above.  We  now  have  to  consider  which  of  the  reactions 
of  the  nervous  system  are  to  be  called  purposive,  and  which 
are  to  be  looked  upon  as  merely  random. 

One  of  the  most  striking  features  of  the  developed  nervous 


MATERIALISM  161 

system  as  compared  with  the  primitive  system  is  that  a 
stimulus  does  not  give  immediate  rise  to  an  action.  In  the 
elementary  animal,  stimulus  is  promptly  followed  by  con- 
traction. In  the  highly  developed  animal,  the  stimulus  may 
simply  take  effect  on  the  nervous  system  without  causing 
any  external  response.  The  nervous  system,  however,  is  to 
some  degree  affected  by  the  stimulus,  so  that  at  future 
times  different  actions  will  arise  from  it  from  those  that 
would  have  arisen  if  no  such  stimulus  had  ever  been  experi- 
enced. So,  too,  the  nervous  system  may  initiate  an  action 
without  any  immediately  preceding  external  stimulus.  In- 
stead of  the  primitive  arrangement  by  which  a  stimulus 
elicits  a  simple  and  immediate  response,  a  stimulus  may 
now  impinge  upon  the  nervous  system  and  leave  its  effects 
stored  up  there.  It  buries  itself,  and  is  lost  in  the  complex 
maze  of  nervous  tissue ;  in  so  doing  it  causes  some  modifica- 
tion of  that  tissue,  which  will  thereafter  affect  the  responses 
to  stimuli  upon  it.  The  sequence  of  stimulus  and  response 
is  obscured.  In  a  highly  developed  nervous  system,  the 
stimuli  incessantly  entering  no  longer  bear  any  immediate 
relation  with  the  responses  incessantly  given  out.  The 
brain  provides  a  great  storehouse  and  clearing-ground  for 
nervous  impulses,  so  that  the  impressions  entering  and  the 
impulses  departing  from  it  lose  a  great  part  of  their  imme- 
diate connection.  The  incoming  currents  spend  themselves 
in  effecting  some  rearrangement  of  the  matter  and  energy 
belonging  to  the  brain.  Outgoing  currents  are  similarly  due 
in  very  many  cases  to  rearrangements  occurring  in  the  brain, 
the  product  of  a  number  of  elements  internal  and  external, 
rather  than  to  any  individual  external  stimulus.  To  this 
is  due  what  appears  to  an  outside  observer  as  the  initiating 
power  of  the  brain,  and  all  those  kind  of  activities  known 
to  psychologists  as  choice,  will,  etc. 

We  are  now  in  a  position  to  appreciate  the  true  meaning 
of  those  acts  which  are  described  as  intelligently  purposive. 
Being  deliberate  and  reasoned  activities,  they  are  as  far  as 


162    MODERN  SCIENCE  AND  MATERIALISM 

possible  removed  from  the  simple  type  of  reflex  action  in 
which  response  follows  immediately  on  external  stimulus. 
They  belong  to  the  category  in  which  the  immediate  stimulus 
is  in  the  brain  itself,  and  is  to  be  regarded  as  consisting  of 
rearrangements  of  the  matter  and  energy  contained  in  the 
nervous  substance  of  the  brain.  The  brain  during  conscious- 
ness can  never  be  still,  and  its  unceasing  activities  supply 
the  stimulus,  not  only  for  purposive,  but  for  all  actions 
of  an  intellectual  character.  Now  this  permanent  cerebral 
activity  can  be  divided  into  a  number  of  different  types, 
known  psychologically  by  such  names  as  memory,  imagina- 
tion, reason,  etc.  Although  nervous  physiology  has  not  yet 
advanced  far  enough  to  enable  us  to  say  \vhat  are  the 
different  kinds  of  material  processes  in  the  brain  correspond- 
ing to  these  psychical  processes,  yet  there  is  no  doubt  that 
the  psychical  distinction  is  based  upon  some  actual  distinc- 
tion in  the  corresponding  activities  occurring  in  the  brain. 
Among  these  cerebral  processes  is  that  which  is  known 
psychologically  as  a  desire  for  some  external  object  or  event, 
a  visualization  of  some  external  phenomenon  as  an  end  or 
purpose  to  be  attained.  This  desire  may  then  act  upon  efferent 
nerves  and  give  rise  to  the  activities  which  we  know  as  pur- 
posive. The  essence  of  a  purposive  action,  and  the  standard  by 
which  it  is  distinguished  from  other  kinds  of  actions,  is  that 
the  "  end "  to  which  the  action  leads  was  previously  repre- 
sented in  the  brain  of  the  agent,  and  composes  the  stimulus 
of  action.  The  compound  stimulus  arises,  as  I  have  said, 
from  the  composition  of  large  numbers  of  elementary  stimuli 
previously  received.  It  consists  psychologically  of  a  faint 
representation  of  the  sensation  which  would  be  vividly  pre- 
sented by  the  realization  of  some  outward  occurrence.  And 
when  this  faint  representation  actually  functions  as  a  stimulus 
which  innervates  the  muscles  whose  contraction  brings  about 
the  external  occurrence  represented,  we  have  what  is  called 
an  action  of  intelligent  purpose. 

Hereafter  the  analysis  is  identical  with  that  employed  in 


MATERIALISM  163 

the  description  of  unintelligent  purpose.  The  only  differ- 
ence is  that  the  stimulus  which  in  the  latter  case  consisted 
of  a  simple  external  contact,  is  replaced  by  a  complex 
cerebral  pattern,  based  upon,  and  produced  by,  a  large 
number  of  these  stimuli  acquired  at  various  former  periods, 
and  of  course  determined  by  the  structure  of  the  brain. 
It  may  be  asked  by  what  process  it  happens  that  a  faint 
psychical  (or  cerebral)  representation  of  some  desired  sensa- 
tion can  give  rise  to  just  that  complicated  series  of  muscular 
activities  needed  for  the  actual  realization  of  this  sensation. 
The  answer  is  the  same  as  in  the  case  of  unintelligent  pur- 
pose, when  we  inquired  how  the  stimulus  provided  by  contact 
of  a  food-particle  set  up  just  the  right  contractions  for 
absorbing  that  particle  into  the  substance  of  the  organism. 
The  answer  suggested  was  Natural  Selection.  In  all  cases 
where  the  complex  cerebral  stimulus  causes  a  muscular 
activity  that  does  not  happen  to  meet  the  end  in  view, 
the  organism  is  extinguished.  Only  that  small  minority 
survive  in  which  the  correct  muscular  activity  is  brought 
about.  A  new  factor  is  indeed  introduced,  owing  to  the 
circumstance  that  the  brain  is  functionally  (and  therefore  in 
some  way  histologically)  excessively  pliable,  and  owes  more 
of  its  ultimate  development  to  education  and  environmental 
influences  than  is  the  case  with  the  nervous  apparatus  of 
inferior  organisms.  To  this  extent  Natural  Selection  is  re- 
placed by  a  less  rigid  discipline.  Error  need  not  result  in 
extinction,  but  merely  in  pain  or  in  privation  of  the  end 
desired.  This  pain  or  privation  constitutes  a  new  stimulus 
which  combines  with  the  many  other  elements  in  the  previous 
cerebral  pattern,  and  suffices  to  intermit  further  muscular 
activity  of  the  kind  which  has  been  injurious.  In  propor-" 
tion  as  the  animal's  educability  is  developed,  the  rigorous 
consequences  of  Natural  Selection  are  mitigated.  The  old 
process  of  trial  and  error  continues,  but  it  is  no  longer  a 
process  of  immediate  life  and  death.  Education  itself,  or 
the  information  gained  from  the  knowledge  and  experience 


164    MODERN  SCIENCE  AND  MATERIALISM 

of  others,  largely  contributes  the  elements  of  that  complex 
cerebral  pattern  which  acts  as  the  stimulus  to  purposive 
activities. 

Intelligent  purpose,  like  unintelligent  purpose,  is  then 
only  a  name  given  to  a  particular  kind  of  incident  in  the 
midst  of  the  eternal  redistribution  of  matter  and  motion 
under  blind  mechanical  laws.  It  is  in  perfect  harmony  with 
that  materialistic  scheme ;  it  can  be  stated  in  terms  of  the 
purest  mechanism.  As  the  matter  and  motion  undergo 
their  invariable  and  unalterable  redistribution,  we  naturally 
find  ourselves  more  interested  in  some  phases  of  it  than 
in  others ;  and  in  one  class  of  evolving  events  we  are 
so  interested  and  we  have  such  frequent  occasion  to  refer  to 
them,  that  we  denominate  them  by  a  special  name — the 
name  of  purposive.  By  this  name  we  designate  the  majority 
of  those  redistributions  which  issue  from  the  little  whirl- 
pools of  matter  and  energy  called  organisms,  and  those 
factors  in  particular  by 'which  the  immediate  continuance 
of  such  whirlpools  is  ensured. 

I  have  now  dealt  with  the  law  of  universal  causation,  and 
with  the  doctrine  of  teleology.  It  remains  only  to  say  a 
few  preliminary  words  about  the  third  main  pillar  ot 
materialism — the  assertion  of  monism,  that  is,  that  there 
are  not  two  kinds  of  fundamental  existences,  material  and 
spiritual,  but  one  kind  only.  This  doctrine  forms  the  subject 
of  the  next  chapter.  For  simplifying  the  discussion,  it  will  be 
as  well  at  once  to  dismiss  from  consideration  all  those  kinds 
of  spiritual  entities  imagined  by  religious  believers.  The 
Victorian  writers  said  on  this  subject  nearly  all  that  could 
be  said,  and  interest  now  attaches  only  to  those  problems 
of  matter  and  spirit  which  they  left  unsolved.  I  shall,  there- 
fore, confine  myself  to  an  attempt  to  reduce  the  last  strong- 
hold of  dualism ;  to  ascertain  the, jrelaiioii_between  mind  and 
body ;  to  show  that  mental  manifestations  and  bodily  mani- 
festations are  not  two  different,  things,  as  generally  supposed, 
but  one  and  the  same  thing  appearing  under  different  aspects. 


MATERIALISM  165 

I  shall  not  attempt  to  deal  with  any  of  the  so-called  "  non- 
material  "  existences  with  the  exception  of  mind  ;  for  if  mind 
can  be  identified  with  matter,  all  other  kinds  of  non-material 
entities  must  lapse,  even  those  described  by  religious 
systems. 

It  has  often  been  observed  that  the  progress  of  knowledge 
has  involved  strong  tendencies  towards  monism  and  away 
from  all  kinds  of  dualism.  The  early  philosophers  were  fond 
of  establishing  fundamental  antitheses,  such  as  between  wet 
and  dry,  hot  and  cold,  light  and  dark,  male  and  female,  etc.1 
Organic  and  inorganic,  animal  and  plant,  were  likewise 
regarded  as  being  in  radical  opposition.  These  bi-polar 
theories  have  all  given  way  to  monistic  conceptions  in  modern 
science.  The  same  evolution  has  occurred  in  our  ideas  both 
of  energy  and  of  matter.  Heat,  light,  sound,  motion,  etc., 
were  formerly  regarded  as  being  so  many  independent  mani- 
festations ;  now  they  are  known  to  be  fundamentally  the 
same,  and  any  one  kind  of  energy  can,  at  all  events  in  theory, 
be  transformed  into  any  other  kind  of  energy.  So  with 
reference  to  matter.  The  chemical  elements,  formerly  regarded 
as  wholly  distinct  from  one  another,  are  now  looked  upon  as 
being  all  developed  from  one  common  type.  It  is  therefore 
altogether  in  accordance  with  what  we  should  expect  from 
the  evolution  of  knowledge,  that  the  rigid  distinction  pre- 
viously drawn  between  mind  and  matter  should  be  found 
untenable,  and  that  these  two,  apparently  opposed,  mani- 
festations should  be  seen  to  have  a  common  basis.  With 
recognition  of  this  truth,  complete  continuity  and  uniformity 
will  be  established  between  all  classes  of  phenomena,  and 
philosophical  discussion  can  only  turn  on  what  particular 
kind  of  monism  we  are  to  accept.  The  treatment  of  this 
subject  is  postponed  to  the  following  chapter. 

At  present  we  have  shown  how  the  law  of  causation  and 
how  the  conception  of  purpose  are  essentially  materialistic 
phenomena.  The  prevailing  confusion  as  regards  causation 

1  History  of  Biology,  by  L.  C.  Miall,  p.  66. 


166    MODERN  SCIENCE  AND  MATERIALISM 

is  due  to  an  intrusion  of  the  subjective  method  into  a  purely 
objective  problem.  There  is  no  transcendental  difference 
between  "  how  "  and  "  why."  When  we  say  "  why  "  an  event 
occurs,  we  are  merely  describing  one  element  in  the  total 
story  as  to  "  how  "  it  occurred — that  element  which  for  the 
moment  excites  our  subjective  attention.  Regarding  all 
processes  in  the  Universe  as  a  redistribution  of  matter  and 
energy,  the  cause  of  any  event  is  found  by  naming  the  ante- 
cedent distribution  of  the  matter  and  energy  involved  in  that 
event.  In  practical  life,  we  usually  refer  only  to  one  aspect 
of  this  total  u cause,"  and  we  then  use  the  word  "cause"  in 
the  limited  sense  suggested  by  our  present  interest. 

So,  also,  the  difficulty  as  regards  teleology  is  due  to  con- 
fusion between  the  subjective  and  the  objective.  In  the 
continuous  flow  of  matter  and  energy,  we  single  out  those 
items  which  chance  to  have  a  special  bearing  on  our  own 
existence,  and  call  them  purposive.  If  interpreted  by  Natural 
Selection,  they  are  seen  at  once  to  be  purely  mechanistic. 
Not  that  it  is  necessary  to  invoke  Natural  Selection  for 
such  an  explanation ;  purposive  results  may  be  achieved 
by  mechanistic  methods  other  than  Natural  Selection,  and 
Darwin's  theory  in  the  foregoing  discussion  has  merely  been 
used  as  a  convenient  illustration  of  one  way  in  which  purpose 
can  be  rendered  in  terms  of  mechanism. 

As  regards  intelligent  purpose,  as  evinced  by  human  beings, 
the  same  principle  holds  good.  In  this  case,  some  definite 
desired  end  is  attained  by  an  act  of  definite  will.  The  chain 
of  material  sequences  lies  mainly  in  the  brain  of  the  agent. 
The  final  consummation  is  preceded  by  particular  cerebral 
states  known  as  desire  and  will.  All  those  sequences  into 
which  these  states  enter  at  some  stage  are  termed  intelli- 
gently purposive.  Sequences  into  which  they  do  not  enter 
are  regarded  as  mechanical.^  Yet  there  is  between  them  no 
objective  difference.  The  difference  is  purely  subjective,  and 
relative  to  ourselves.  All  confusion  arises  from  the  old 
anthropocentric  fallacy — the  supreme  difficulty  of  taking  up 


MATERIALISM  167 

a  wholly  external  and  objective  attitude  towards  ourselves. 
Just  as  the  savage  supposes  the  whole  Universe  to  be  specially 
created  for  the  benefit  of  himself  or  his  tribe ;  just  as  the 
more  civilized  man  supposes  the  Universe  to  be  specially 
subservient  to  the  human  race ;  so  in  the  most  recondite 
problems  of  philosophy  our  arguments  tend  to  be  vitiated 
by  infusion  of  the  subjective  element,  in  such  a  way  that 
we  read  into  external  nature  the  human  interests  and 
egocentric  habits  which  belong  to  our  own  minds. 

I  shall  conclude  this  chapter  with  a  few  words  as  to  the 
scientific  method  espoused  by  materialism.  It  is  the  method 
of  observation  and  experiment,  and  these  two  are  in  reality 
the  same.  An  experiment  is  only  an  observation  under 
artificial  conditions.  When  we  observe  some  manifestation 
occurring  under  natural  conditions,  our  method  is  that  of 
observation ;  when,  on  the  other  hand,  we  observe  some 
manifestation  occurring  under  conditions  that  we  have  our- 
selves purposely  established,  our  method  is  that  of  experiment. 
The  advantage  of  experiment  over  simple  observation  is  partly 
that  we  can  produce  the  required  phenomenon  at  a  time  and 
place  convenient  to  ourselves,  and  partly  that  we  have  a  more 
exact  knowledge  of  the  conditions  under  which  it  occurs. 
Experiment  is  a  process  of  analysis.  We  select  certain 
conditions,  and  exclude  certain  other  conditions,  and  we  then 
see  what  happens.  If  we  were  debarred  from  experiment  we 
should  be  debarred  from  analysis,  and  often  compelled  to 
wait  long  periods  before  Nature  furnished  us  with  an  example 
of  the  particular  phenomenon  we  desired  to  witness. 

Admitting  that  observation  and  experiment  are  two 
varieties  of  the  same  thing,  we  find  at  least  two  rival 
methods  in  very  frequent  use.  The  one  is  that  of  innate 
knowledge.  It  is  held  by  some  that  knowledge  of  detailed 
and  complicated  phenomena  is  implanted  within  us  by 
Nature  or  God,  wholly  independent  of  experience  acquired 
by  observation,  experiment,  or  education.  Such  is  the 
opinion  of  those  who  set  up  "  faith  "  against  science.  Such 


168    MODERN  SCIENCE  AND  MATERIALISM 

again  is  the  opinion  of  philosophers  like  Bergson,  who  rank 
instinct  as  a  rival  method  to  intellect  for  the  acquisition 
of  knowledge.  I  have  already  dealt  with  this  superstition 
in  a  previous  work,  and  shall  say  no  more  about  a  doctrine 
so  utterly  at  variance  with  the  tone  both  of  science  and 
materialism. 

A  more  serious  rival  to  the  methods  of  observation  and 
experiment  is  the  deductive  method.  It  is  more  serious, 
because  it  is  a  genuine  and  true  method.  It  is  often  not  only 
a  reliable,  but  an  absolutely  certain  method  of  discovering 
truth,  and  the  only  method  by  which  such  truth  could  ever 
be  discovered.  It  is  therefore  infinitely  different  from  the 
spurious  method  of  instinct,  which  is  always  and  invariably 
false.  It  is  just  the  very  power  of  the  deductive  method, 
under  certain  conditions,  that  constitutes  it  so  dangerous  an 
adversary  of  observation  and  experiment.  For  it  is  univer- 
sally applied  in  wider  spheres  than  that  to  which  it  is 
appropriate.  In  mathematics,  and  in  a  large  part  of  physics, 
the  deductive  method  is  paramount.  In  geology,  biology, 
and  physiology,  which  are  still  in  the  inductive  stage,  any 
kind  of  deduction  has  to  be  employed  with  the  greatest 
caution  and  circumspection,  and  this  necessity  arises  from  the 
fact  that  in  these  inductive  sciences  the  phenomena  observed 
are  commonly  due  to  the  interaction  of  a  very  large  number 
of  separate  factors.  Now  deduction  can  only  deal  with 
phenomena  in  which  the  causative  factors  are  very  few  and 
simple,  as  is  the  case  in  mathematics.  I  will  take  an  example 
from  political  controversy. 

Socialists  affirm  that  slum-dwellers,  badly  housed  and  fed, 
undergo  some  physical  deterioration  as  a  result,  and  that 
this  deterioration  being  inherited  by  their  children,  of  whom 
they  produce  a  large  number,  involves  a  deterioration  of  the 
race.  This  deduction  is  rather  conspicuously  false.  In  the 
first  place,  assuming  that  slum-dwellers  do  become  physically 
degenerate,  there  is  no  evidence  whatever  that  such  degenera- 
tion is  inherited  by  their  children.  On  the  contrary,  the 


MATERIALISM  169 

great  preponderance  of  biological  opinion  is  opposed  to  any 
such  view.  In  the  next  place,  supposing  that  the  degenera- 
tion were  inherited,  there  is  still  no  evidence  that  any  racial 
degradation  would  result.  The  process  might  simply  be  one 
of  a  wholesome  extinction  of  weak  stocks.  I  do  not  know 
whether  this  is  so  or  not :  all  that  I  do  know  is  that  the 
deductive  method  is  applied  in  their  argument  several  times 
over  where  it  is  inapplicable,  and,  in  consequence,  that  the 
conclusion  reached  has  no  relation  to  the  truth,  one  way  or 
the  other.  It  is  affirmed,  on  the  other  hand,  that  nations 
which  have  lived  in  slums  for  many  centuries  have  not  in 
consequence  degenerated,  and  this  observation,  if  correct, 
is  of  more  value  than  a  whole  multitude  of  convergent 
deductions. 

But  the  anti-socialist  arguments  are  equally  deductive ; 
and  it  is  for  this  reason  that  so  much  of  Herbert  Spencer's 
social  writings  are  worthless.  He  argued  that  if  the 
whole  nation  is  taxed  to  subsidize  the  poorer  sections  of 
the  people,  ruin  must  result;  for,  in  general,  the  poor  are 
the  feeblest  part  of  the  community.  You  are  therefore  taking 
money  from  the  strong  to  give  to  the  weak ;  you  are  making 
it  more  difficult  for  the  strong  to  survive,  and  easier  for  the 
weak  to  survive.  Ensuing  generations  will,  therefore,  be  weaker 
than  the  present.  Furthermore,  by  giving  money  or  goods 
to  those  who  have  little  of  either,  you  discourage  providence, 
and  national  impoverishment  will  result. 

Now  here  we  have  a  string  of  deductions  in  a  sphere  where 
deduction  is  altogether  unreliable.  There  are  in  all  pro- 
bability a  large  number  of  factors  involved  in  the  causation 
of  racial  degeneracy,  as  of  national  impoverishment.  Spencer 
isolates  one  or  two  such  factors  on  which  his  attention  happens 
to  be  directed,  and  forgets  the  possibility,  or  indeed  the 
certainty,  that  the  results  of  these  few  factors  will  be  alto- 
gether drowned  amidst  the  rest.  When  compulsory  national 
insurance  was  instituted  in  England,  it  was  prophesied  that 
the  sale  of  patent  medicines  would  be  largely  diminished ;  for 


170     MODERN   SCIENCE  AND  MATERIALISM 

when  the  people  can  get  their  medicines  free,  it  seems  obvious 
that  they  will  not  continue  to  purchase  expensive  drugs, 
which  are  in  every  respect  inferior  to  those  they  can  have 
for  nothing.  This  deduction  seemed  so  obvious  that  the 
Chancellor  of  the  Exchequer  budgeted  for  a  large  falling-off 
of  revenue  on  patent-medicine  stamps.  Yet,  when  the  Act 
came  into  force,  a  very  remarkable  increase  occurred  in  the 
sale  of  patent  medicines.  A  deduction  which  seemed  at  the 
time  to  be  absolutely  certain  and  necessary,  was  completely 
falsified  by  the  facts. 

Instances  of  misapplied  deduction  might  be  multiplied 
ad  infinitum ;  the  whole  world  of  politics  is  riddled  with  it. 
For  the  present,  I  have  only  to  note  that  a  tendency  exists  to 
use  deduction  with  far  too  much  freedom  in  biology  and  all 
its  allied  and  derivative  sciences. 

On  the  other  hand,  deduction  cannot  be  dispensed  with, 
even  in  these  sciences.  Take  the  following  proposition,  which 
is  exclusively  empirical  in  character.  All  white  male  cats  that 
have  blue  eyes  are  deaf.  The  proposition  is  interesting,  but 
of  very  limited  value  to  science  unless  it  is  linked  up  with 
other  known  facts  of  biology.  Standing  alone,  it  teaches 
little.  We  are  at  once  met  by  the  question,  why  are  they 
deaf?  And  to  answer  this  we  are  driven  to  resort  to  a 
moderate  degree  of  deduction  and  generalization,  by  means 
of  which  an  answer  may  perhaps  be  attained  without  serious 
danger  of  error.  Without  deduction  biology  would  be 
nothing;  and  perhaps  the  most  fundamental  difference 
between  the  trained  biologist  and  the  raw  student  is  that  the 
former  knows  by  experience  when  he  may  safely  use  deduction, 
and  the  latter  does  not.  But  even  the  best  biologist  must 
often  make  mistakes,  and  a  vast  acquaintance  with  details  is 
often  a  less  useful  possession  than  a  mind  of  philosophical 
amplitude  backed  by  a  sufficient  though  smaller  acquaintance 
with  details.  The  specialist  Cuvier  formed  a  less  accurate 
idea  of  species  than  the  philosopher  Goethe. 

The  whole  subject,  in  short,  is  extremely  difficult ;  and  the 


MATERIALISM  171 

difficulty  of  understanding  the  correct  use  of  deduction  is 
accountable  for  the  fact  that  the  biological  sciences  are 
broken  up  into  so  many  diverse  schools  of  thought,  among 
whom  no  agreement  can  be  attained.  It  is  probably  im- 
practicable to  make  any  suggestions  for  rules  on  this  abstruse 
subject.  My  purpose  here  is  merely  to  indicate  that  the 
general  reader  and  non-specialist  scholar  is  certain  to  use 
deduction  with  excessive  frequency,  unless  very  carefully 
warned  in  advance.  All  the  emphasis  must  be  laid,  therefore, 
on  observation  and  experiment.  The  Baconian  method  is 
nearly  always  laborious,  expensive,  and  difficult ;  it  is  very 
often  utterly  impossible  of  application ;  yet  it  is  the  only 
method  by  which  truth  can  be  safely  sought.  Deduction, 
which  can  be  carried  out  by  a  few  minutes1  thought  in  an 
arm-chair,  is  easy  and  cheap ;  hence  the  overwhelming  tend- 
ency to  employ  it.  In  science  and  philosophy  no  solution 
that  has  been  reached  with  little  trouble  is  likely  to  be  of 
the  slightest  value,  and  most  of  the  things  we  really  want  to 
know  are  not  ascertainable  by  any  degree  of  effort  whatever. 
It  remains  only  to  indicate  the  heuristic  value  of  the 
doctrine  of  materialism.  To  many  it  may  seem  useless  to 
formulate  a  philosophy  of  this  or  any  other  kind.  Never- 
theless, such  philosophies  provide  a  general  outlook  or  point 
of  view  on  scientific  problems  which  is  in  the  highest  degree 
valuable  and  fertile  for  future  progress.  We  learn  from  a 
sound  materialistic  philosophy,  not  mere  individual  facts, 
but  the  kind  of  way  in  which  Nature  hangs  together. 
When  we  are  confronted  with  a  new  scientific  problem,  our 
philosophy  may  tell  us  at  once  that  the  solution  is  along 
certain  lines  of  investigation,  and  it  may  expressly  exclude 
other  lines  of  investigation.  We  shall  investigate  alleged 
instances  of  telepathy  without  the  slightest  reference  to  any 
of  the  silly  popular  theories  on  the  subject.  We  shall  study 
problems  of  conduct  and  of  thought  from  the  point  of  view 
of  physico-chemical  mechanism,  and  shall  not  improbably 
reach  conclusions  of  great  importance,  that  we  never  could 


172    MODERN  SCIENCE  AND  MATERIALISM 

have  reached  without  such  general  outlook.  In  morals  and 
politics  we  shall  understand  the  motives  of  mankind,  which 
to  others  must  remain  for  ever  sealed.  Infinite  capacity  of 
doing  good  necessarily  follows,  if  we  happen  to  be  philan- 
thropically  minded.  Materialism,  in  short,  acts  as  a  general 
guide  and  starting-point  for  investigation,  which  must  furnish 
its  possessor  with  unusual  powers,  whether  in  research  or  in 
action. 

I  regard  the  establishment  of  a  materialistic  philosophy, 
therefore,  as  a  consummation  of  the  highest  utility,  partly 
on  the  ground  of  the  destruction  of  superstition,  but  still 
more  on  the  ground  that  it  inculcates  a  particular  mental 
orientation  which  is  productive  of  a  powerful  impetus  towards 
scientific  progress.  It  involves  a  sound  general  outlook  on 
Nature,  the  suppression  of  falsity,  and  the  triumph  of  a 
true  method. 

To  those,  however,  whose  inclinations  dispose  them  to 
deny  the  utility  of  so  unpopular  a  philosophy,  I  reply 
on  still  higher  grounds.  I  reply  that  it  does  not  matter 
whether  this  philosophy  is  useful  or  not.  Truth  is  an  ideal 
which  is  worthy  to  be  pursued  for  its  own  sake,  without 
reference  to  its  utility.  Philosophers  and  men  of  science 
are  not  like  merchants  and  tradesmen,  who  deal  in  com- 
modities on  account  of  their  utility  or  of  some  popular 
demand  for  such  commodities.  Our  purpose  is  different 
from  that  of  the  tradesman.  The  goods  we  supply  need 
have  no  practical  utility  whatever ;  and  so  far  from  being 
adapted  to  a  popular  demand,  we  continue  to  turn  out  our 
goods  even  in  spite  of  extreme  popular  dislike.  We  deal  in 
truth,  and  not  in  values.  Doubtless,  many  of  the  greatest 
utilities  have  sprung  from  apparently  the  most  transcen- 
dental investigations.  Doubtless  it  is  true  that  the  highest 
stages  of  civilization  have  invariably  been  characterized  by 
studies  and  speculations  that  are  as  far  as  possible  removed 
from  every  consideration  of  utility.  We  do  not  seek  to 
justify  our  course  by  any  such  considerations;  nor  is  it 


MATERIALISM  173 

worth  our  while  to  take  up  the  easy  task  of  proving  that 
the  happiness  and  progress  of  humanity  have  depended  far 
more  on  the  transcendental  researches  of  the  savant  than  on 
the  humble  utilitarianism  of  the  tradesman.  It  is  enough 
for  us  to  have  before  us  the  great  ideal  of  truth,  and  to 
know  that,  even  though  we  may  be  mistaken,  we  have  done 
our  best  towards  the  enlightenment.  Our  motto  was  given 
us  by  Pasteur — "  Travaillons."  Let  us  continue  to  work 
without  consciousness  of  any  ulterior  end ;  let  us  continue 
to  pursue  our  labours  after  knowledge,  to  whatever  unknown 
goal  they  may  lead  us. 


CHAPTER  VI 

IDEALISM 

WE  at  length  reach  the  final  stage  in  presenting  the  philo- 
sophy of  Scientific  Materialism.  The  preceding  chapters 
have  shown  that  no  intelligible  explanation  of  events  can  be 
given  from  any  standpoint  except  of  a  materialistic  nature. 
There  is  no  place  for  "spirit"  in  the  subject-matter  dealt 
with  by  astronomers  or  by  physicists.  Biology  is  equally 
founded  on  a  basis  of  pure  materialism.  In  physiology  the 
theory  of  vitalism  which  imagines  a  spiritual  intervention 
in  physiological  processes  is  hopelessly  discredited,  and  has 
now  been  abandoned  by  all  physiologists  in  practice  and  by 
the  great  majority  also  in  theory.  We  are  led,  therefore, 
inevitably  to  the  conclusion  that  the  causation  of  events  of 
every  kind  is  purely  materialistic.  We  have  not  yet  in  the 
course  of  our  studies  come  across  any  kind  of  causation 
that  is  spiritual  in  character,  as  opposed  to  physical.  The 
Universe  is  governed  by  the  physical  laws  of  matter,  even 
to  the  most  refined  and  complex  processes  of  the  human 
mind. 

Are  we  to  infer  from  this  that  materialism  is  the  only 
true  philosophy  ?  Such  an  inference  is  not  justified  by  any 
evidence  we  have  yet  considered.  The  only  inference  we  are 
entitled  at  present  to  draw  is  that  materialism  is  the  basis 
of  natural  science.  Science  necessarily  assumes  materialism 
for  its  foundation ;  it  rests  upon  materialism  as  chemistry 
rests  upon  the  atomic  theory.  But  just  as  chemists  long 
looked  upon  the  atomic  theory  simply  as  a  good  working 
hypothesis,  without  committing  themselves  to  a  belief  in  its 
absolute  truth,  so  we  are  now  in  the  position  of  recognizing 

174 


IDEALISM  175 

materialism  as  a  good,  and  the  only  good,  working  hypothesis, 
without  having  yet  investigated  the  question  of  its  absolute 
truth.  Whether  any  solution  is  possible  to  such  a  question, 
and  if  so  what  solution,  is  the  subject  to  which  we  have  now 
to  address  ourselves. 

To  the  ordinary  educated  adult,  the  first  and  so-called 
common-sense  view  seems  to  disclose  two  utterly  dissimilar 
kinds  of  existence,  known  respectively  as  mind  and  matter. 
And,  in  consequence,  so-called  common-sense  philosophers, 
such  as  Herbert  Spencer,  have  affirmed  that  the  difference 
between  mind  and  matter  is  greater  than  any  other  differences 
that  come  within  the  range  of  our  consciousness.  Everybody 
thus  starts  studying  philosophy  as  a  dualist,  and  many  of  the 
problems  of  philosophy  arise  out  of  the  question  as  to  the 
relationship  between  these  two  alleged  dissimilar  existences. 

But  why  are  we  thus  to  start  from  the  pre- formed  impres- 
sions of  the  adult  ?  In  doing  so  we  come  to  the  study  of 
philosophy  in  its  middle:  we  already  bring  with  us  to  the 
subject  a  dualistic  conclusion  which  should  be,  if  it  is  true, 
at  the  end  and  not  at  the  beginning  of  a  philosophical 
inquiry.  I  propose,  therefore,  to  commence  this  study,  not 
from  the  experiences  of  the  educated  adult,  but  from  the 
experiences,  as  far  as  they  can  be  ascertained,  of  a  newly- 
born  infant,  whence  I  shall  trace  them  to  the  more  developed 
outlook  of  the  adult. 

We  at  once  observe  that  the  baby's  experiences  are  not 
such  as  to  yield  a  theory  of  dualism,  but  a  theory  of  monism. 
The  baby  does  not  have  two  utterly  dissimilar  types  of 
experiences ;  it  has  only  one ;  and  that  one  takes  the  form 
of  a  succession  of  sensations  of  varying  intensity  and  kind. 
It  possesses  no  instinctive  knowledge  of  matter  or  of  dis- 
tance. The  impression  derived  from  the  eyes  is  merely 
that  of  a  disordered  mixture  of  colours  and  shades.  The 
visual  impression  which  gives  rise  in  an  adult  to  the  concep- 
tion of  a  table,  is  to  a  baby  no  more  than  a  congeries  of 
colours,  of  differing  brightness  or  darkness.  It  conveys  no 


176    MODERN  SCIENCE  AND  MATERIALISM 

idea  of  solidity,  or  hardness,  or  distance,  or  any  other  material 
attribute. 

The  sense  of  touch,  in  the  same  way,  yields  nothing  more 
than  a  series  of  isolated  sensations.  The  prick  of  a  pin  is 
known  only  as  a  sensation.  It  is  not  referred  to  any  outer 
world ;  it  is  not  associated  with  the  idea  of  matter ;  it  is  not 
recognized  in  any  way :  it  is  merely  a  sensation,  meaningless 
and  unlocalized. 

The  emotions  belong  to  the  same  category.  They  are 
mere  units  in  the  succession  of  sensations,  differing  perhaps 
by  their  greater  intensity,  but  meaning  nothing.  The  baby, 
moreover,  is  not  only  completely  ignorant  of  any  external 
world,  it  is  completely  ignorant  of  its  own  body.  In  short, 
the  entire  experience  of  a  baby  is  psychical  in  character. 
It  knows  nothing  of  matter ;  and  if  it  were  endowed  with 
the  power  to  form  philosophical  theories,  it  would  never 
divide  up  the  Universe  into  mind  and  matter.  It  would  be 
cognizant  only  of  one  order  of  existences — that  which  adults 
describe  as  psychical. 

The  next  step  in  our  inquiry  is  to  ascertain  how  the 
conception  of  matter  first  arises,  and  this,  fortunately,  is 
a  question  on  which  the  facts  are  pretty  clear. 

Sensations  soon  cease  to  be  isolated  units  and  enter  into 
associations  with  one  another.  A  particular  visual  sensation 
is  accompanied  on  frequent  occasions  by  particular  tactual 
sensations.  A  visual  sensation  of  brown  colour  is  associated 
with  tactual  and  muscular  sensations  of  hardness,  resistance, 
smoothness,  and  so  on.  Tactual  sensations  in  general  become 
universally  associated  with  visual  sensations;  and  special 
tactual  sensations  such  as  pricks  become  associated  with 
special  visual  sensations,  such  as  the  appearances  of  sharp 
points.  In  short,  a  certain  order  begins  to  appear  out  of  the 
hotch-potch  of  disconnected  sensations.  They  are  no  longer 
perfectly  liquid,  appearing  and  disappearing  at  hazard  ;  they 
begin  to  clot.  The  arrival  in  consciousness  of  one  sensation 
begins  with  some  regularity  to  be  the  sign  of  other  coming 


IDEALISM  177 

sensations.  The  sensations  become  combined  or  associated 
into  groups,  and,  as  time  goes  on,  the  groups  become  larger. 
One  sensation  does  not  suggest  one  other  merely,  but  several 
others.  These  little  associated  groups  of  sensations  must 
appear  first  as  islands  in  the  midst  of  the  primitive  sensational 
ocean.  They  appear,  of  course,  long  before  any  power  of 
speech  is  acquired ;  but  they,  nevertheless,  are  the  foundation 
of  what  adults  call  "matter."  We  may  suppose  that  the 
conception  of  matter  originates  with  the  association  of 
certain  colour  sensations  with  the  sensation  of  resistance. 
Other  sensations  are  soon  added;  and  the  individual  sen- 
sations which  compose  the  group  are  what  adults  term  the 
"properties  of  matter." 

One  of  these  properties,  which  is  by  no  means  among  the 
earliest  to  appear,  is  that  of  occupying  space.  A  very  young 
child  is  hopelessly  at  sea  in  its  attempts  to  estimate  the 
distances  of  objects ;  even  objects  close  at  hand  are  mis- 
calculated, and  remote  objects  present  insuperable  difficulty. 
A  child  will  reach  for  the  moon  when  it  is  already  many 
months  old.  The  reason  for  this  is  that  the  cluster  of 
sensations  which  give  rise  to  the  idea  of  distance  is  somewhat 
complex.  There  are,  firstly,  the  lights  and  shades  of  the 
object  itself,  the  brilliancy  or  dullness  of  its  colours ;  there 
is,  secondly,  the  sensation  which  accompanies  particular 
degrees  of  convergence  of  the  optical  axes ;  there  is,  thirdly, 
the  sensation  characteristic  of  the  contraction  of  the  muscles 
which  regulate  the  amount  of  the  convexity  of  the  lenses  in 
the  two  eyes  ;  and  there  are  others  less  important.1  All  these 
have  to  be  associated  with  one  another  and  with  the  sensation 
of  the  muscular  effort  required  to  reach  the  object,  before 
any  idea  of  distance  or  solidity  can  be  obtained.  To  an 
adult,  a  flat  object  like  a  drawing  may  be  made  to  look  solid 
by  artificial  production  of  one  of  the  sensations  which  enter 

1  The  great  importance  of  muscular  adjustment  of  the  eyes  in  the 
perception  of  space  and  of  matter  suggests  a  biological  explanation  of 
the  fact  that  out  of  the  twelve  cranial  nerves,  no  fewer  than  three  have 
an  oculo-motor  function. 


178    MODERN  SCIENCE  AND  MATERIALISM 

into  the  conception  of  solidity,  as  happens  with  the  stereo- 
scope. Thus  we  find  that  the  earliest  events  in  a  child's 
mental  life  are  the  coalescence  into  groups  of  some  of  the 
previously  isolated  elements  of  consciousness.  The  sen- 
sational sea,  from  being  entirely  liquid,  begins  to  solidify. 
The  sensations  no  longer  move  among  themselves  with 
perfect  freedom  and  disorder;  many  of  them  have  become 
coherent ;  they  have  solidified,  and  begin  to  be  recognized  as 
matter. 

With  increasing  "  knowledge "  the  little  clusters  of  sen- 
sations continually  swell ;  new  properties  of  matter  are 
"  discovered " ;  until  at  length  we  reach  the  learning  of  the 
physicist,  whose  conception  of  matter  is  associated  with  an 
infinitely  greater  diversity  of  properties  than  is  dreamt  of  by 
the  child.  In  the  infant's  mind,  matter  has  at  first,  perhaps, 
only  two  properties,  colour  and  resistance.  Only  two  sen- 
sations are  loosely  combined  together.  In  the  physicist's 
mind,  the  properties  of  matter  are  numberless.  It  is  divided 
up  into  molecules  and  atoms,  too  small  by  a  millionfold  to  be 
perceived  by  any  microscope,  and  these  are  divided  up  again 
into  particles  still  smaller.  That  is  to  say,  the  number 
of  sensations,  or  possible  sensations,  bound  together  in  the 
physicist's  mind  under  the  title  of  matter  show  little  trace 
of  the  humble  origin  from  which  they  started  to  evolve. 

We  thus  reach  a  justification  to  some  extent  of  philo- 
sophical idealism.  Idealism  insists  upon  the  fact  that  the 
entire  knowledge  and  experience  of  adults  is  purely  psychical, 
just  as  is  undoubtedly  the  case  with  the  baby.  The  adult's 
knowledge  of  matter,  like  that  of  the  baby,  is  gained  only 
through  sense-impressions,  and  the  perceptions  and  inferences 
drawn  from  them.  And  there  is  no  great  alteration  in  the 
quantity  or  variety  of  the  impressions  which  affect  him.  His 
more  advanced  nervous  organization  may  allow  him  to  see  a 
greater  variety  of  colours,  to  hear  a  greater  variety  of  sounds, 
or  to  feel  a  greater  variety  of  tactual  impressions.  But  the 
advance  in  mental  organization  is  altogether  out  of  proper- 


IDEALISM  179 

tion  to  the  increase  in  number  of  the  mere  units  of  conscious- 
ness. It  depends  upon  the  fact  that  those  units  now  bear 
a  meaning ;  they  are  no  longer  kaleidoscopic  and  ephemeral 
as  they  were.  A  particular  set  of  visual  sensations  may  now 
give  rise  to  the  knowledge  of  the  presence  of  a  table.  Those 
sensations  are  not  mere  colour-sensations,  which  tell  nothing, 
as  in  the  baby's  case.  They  suggest  a  portion  of  matter,  of 
a  certain  distance,  a  certain  size,  shape,  use,  hardness,  and 
innumerable  other  qualities.  The  change  is  analogous  to  the 
appearance  of  a  Chinese  puzzle  before  and  after  it  has  been 
solved.  Before,  the  individual  pieces  are  meaningless  and 
occur  at  random.  Afterwards,  the  same  pieces  are  associated 
in  special  ways  together,  so  as  to  carry  a  real  meaning. 

But  if  we  are  committed  to  idealism,  it  is  an  idealism  very 
different  from  what  is  popularly  understood  by  that  doctrine. 
As  before  mentioned,  the  normal  adult  invariably  comes  to 
this  problem  with  the  rooted  preconception  of  two  funda- 
mentally distinct  entities,  mind  and  matter.  By  idealism  he 
then,  of  course,  necessarily  understands  a  doctrine  which 
denies  the  existence  of  matter,  or  looks  upon  matter  merely 
as  a  product  of  imagination,  or  asserts  the  pre-eminence  of 
mind  over  matter.  All  this  is  mere  vain  talking  which  arises 
from  a  complete  misapprehension  of  the  whole  subject. 
Idealism,  as  I  have  described  it,  does  not  deny  the  existence 
or  the  reality  of  matter.  It  simply  states  what  matter  is,  in 
terms  of  consciousness.  It  defines  a  portion  of  matter  as  a 
nucleus  of  associated  sensations.  Those  associated  sensations 
are  just  as  real  as  the  unassociated  reservoir  from  which  they 
sprang.  But,  replies  the  sciolist,  the  things  are  totally  dif- 
ferent. Sensations  are  within  us,  matter  is  outside  of  us  and 
remains  when  the  sensations  called  up  by  it  have  ceased. 

Futile  though  this  criticism  is,  I  recognize  the  inevitable- 
ness  of  its  being  made.  And  the  only  difficulty  in  making  a 
reply  is,  as  I  hope  some  of  my  readers  will  already  perceive, 
the  difficulty  of  lucid  exposition.  I  have  to  contend  with 
that  profound,  deep-rooted  prepossession  of  the  duality  of 


180    MODERN  SCIENCE  AND  MATERIALISM 

mind  and  matter;  a  prepossession  which  has  obsessed  us 
during  the  whole  of  our  lives,  which  has  moulded  the  very 
language  in  which  the  philosopher  has  to  write.  There  is  no 
inherent  difficulty  in  the  subject  itself;  but  the  difficulty  of 
lucid  exposition,  the  difficulty  of  conveying  one's  meaning, 
when  almost  every  word  available  carries  connotations  one 
does  not  intend,  is  almost  insuperable.1 

To  revert,  however,  to  the  criticism  before  me :  matter  is 
outside  us  and  permanent,  sensation  is  inside  us  and  fleeting ; 
how,  then,  can  the  two  be  identified  ?  I  reply  by  asking  what 
is  meant  by  outside  and  inside.  They  are  but  sensations,  of 
the  same  order  as  any  other  kind  of  sensation.  I  have 
already  named  a  few  of  the  sensations  which  go  to  make  up 
the  notion  of  distance.  Those  which  compose  the  notion  of 
outsideness  are  similar  in  character.  The  notion  of  inside- 
ness  is  composed  of  certain  other  types  of  sensation.  Just 
as  matter  is  a  clot  of  sensation,  so  matter,  regarded 
particularly  as  being  outside  of  us,  is  that  same  clot  with 
certain  of  its  component  sensations  holding  attention  for  the 
moment.  Then,  continues  the  idealist,  do  you  assert  that 
the  exteriority  of  matter  is  a  fancy,  and  that  it  exists  really 
within  us  ?  Not  in  the  least.  For  the  notion  of  being  within 
is  just  as  much  a  sensation  as  the  notion  of  being  without. 
When  we  get  down  to  bedrock,  and  are  dealing  only  with 
sensations  as  the  units  of  consciousness,  there  is  no  such 
thing  as  "  without "  or  "  within."  These  themselves  are 
sensations  like  the  others.  If  the  sensations  of  visual  accom- 
modation, etc.,  enter  into  an  associated  clot,  then  we  affirm 
that  the  object  is  without  us.  If  those  sensations  are  not 
included,  but  certain  others  are,  then  we  affirm  that  the 
experience  is  within  us.  In  short,  matter  with  all  its  pro- 
perties, spatial  and  other,  can  be  analyzed  into  a  group  of 

1  In  the  same  way,  William  James  writes  of  his  Radical  Empiricism  : 
{ '  It  presents  so  many  points  of  difference,  both  from  the  common  sense 
and  from  the  idealism  that  have  made  our  philosophic  language,  that 
it  is  almost  as  difficult  to  state  as  it  is  to  think  it  out  clearly."— Essays 
in  Radical  Empiricism,  p.  90. 


IDEALISM  181 

sensations,  isolated  and  lawless  in  the  baby,  but  conjoined 
into  a  close  group  in  the  adult. 

We  begin  now  to  see  the  futility  of  many  of  the  problems 
which  have  for  so  long  vexed  and  puzzled  the  metaphysicians. 
To  begin  with,  there  is  the  absurd  distinction  between 
noumena  and  phenomena ;  there  is  the  confused  idea  of 
things  existing  "  in  themselves  "  as  apart  from  the  way  in 
which  they  appear  to  us.  But  to  the  kind  of  idealistic 
monism  which  I  have  sketched  out,  analysis  brings  down 
everything  at  bottom  to  sensation.  There  is  no  meaning  in 
the  question  whether  anything  is  "  behind  "  matter.  Matter 
is  merely  a  clot  of  sensations,  and  the  question  then  has  to 
be  put,  Is  there  anything  behind  sensation  ?  The  question  is 
futile,  but  it  is  also  meaningless.  For  sensation  is  the  begin- 
ning and  the  end  of  all  knowledge.  The  idea  of  something 
else  being  behind  it  or  causing  it,  is  simply  a  sensation  itself, 
and  no  more.  Sensation  is  the  only  reality  we  have  to 
contend  with,  and  to  ask  whether  there  is  anything  else 
behind  it  more  real,  is  as  reasonable  as  to  ask  whether  there 
is  anything  more  alphabetical  than  the  alphabet.  Sensations 
then  are  real,  in  the  only  meaning  that  that  word  can  ever 
have  for  us  ;  and  since  sensations  are  real,  matter  is  also  real. 
The  hard,  solid  table  on  which  I  am  writing  is  just  as  real  as 
the  sensations  of  strain  and  attention  with  which  I  write. 

Many  further  questions  now  arise  into  view,  and  must  be 
dealt  with  in  the  light  of  the  foregoing  theory.  One  of  the 
most  important  is  to  trace  the  origin  of  the  supposed  duality 
of  mind  and  matter ;  the  relation  of  mind  to  brain  ;  the  idea 
of  personality  ;  the  fallacy  of  solipsism  ;  and  finally  the 
interpretation  of  materialism  and  its  significance  for  science 
and  the  progress  of  knowledge.  I  shall  begin  first  with  the 
origin  of  the  idea  of  personality.  A  common  criticism  brought 
against  idealism  is  that  it  commits  us  to  the  doctrine  of 
solipsism,  that  is  to  say,  the  belief  that  I,  the  ego^  am  the 
only  real  existence,  and  that  other  personalities  are  merely 
figments  of  imagination.  For,  says  the  critic,  you  say  that 


182    MODERN  SCIENCE  AND  MATERIALISM 

all  matter,  and  hence  too  all  human  beings,  are  nothing  more 
than  modes  of  your  associated  sensations,  and  that  is  tanta- 
mount to  the  assertion  that  they  have  not  an  existence  of  the 
same  kind  of  reality  as  you  yourself  with  your  sensations. 
The  criticism,  like  all  other  criticisms  on  idealism,  arises 
from  a  misapprehension  of  the  doctrine  attacked ;  a  misap- 
prehension which  in  this  particular  criticism  is  repeated 
several  times  over.  In  the  first  place,  the  idea  of  I,  or  ego, 
is  foreign  to  idealism  as  I  have  defined  it ;  it  is  as  much  a 
product  of  inference  as  the  idea  of  you  or  any  other  per- 
sonality. It  cannot  be  repeated  too  often  that  we  started 
this  argument  by  taking  isolated  sensations  as  our  sole  data, 
and  association  between  them  as  the  sole  change  which  could 
occur  among  them.  Here  and  there  these  sensations  clot 
and  solidify  into  material  objects.  Among  these  clots  there 
are  many  which  represent,  or  which  are  called,  men  and 
women ;  there  is  one,  with  specially  ramified  associations, 
called  /.  The  grounds  for  believing  in  the  real  existence 
of  other  personalities  are,  therefore,  co-ordinate  with  the 
grounds  for  believing  in  the  real  existence  of  our  own  person- 
ality. Indeed,  in  the  course  of  development,  belief  or  know- 
ledge of  other  personalities  comes  first.  The  infant  knows 
its  mother  as  a  person  before  it  knows  itself  as  a  person  ;  and 
for  some  time  afterwards  it  takes  an  objective  view  of  itself, 
calling  itself,  not  /,  but  by  its  name  ;  even  offering  a  biscuit 
to  its  foot,  and  so  on. 

Still  the  critic  demurs.  You  have  got  over  the  difficulty, 
he  says,  of  attributing  to  the  reality  of  my  existence  a 
validity  less  than  that  of  your  own ;  you  have  explained 
that  you  do  not  regard  me  as  your  sensation,  but  you  still 
regard  me  as  sensation.  When  you  die,  that  sensation  will 
cease.  Will  it  follow,  then,  that  I  also  shall  cease  to  exist  ? 

The  fallacy  embodied  in  this  particular  question  turns 
upon  the  meaning  of  the  word  exist.  Let  us  transcribe  its 
meaning  in  our  idealistic  language.  Here  is  a  certain 
material  object ;  here,  that  is  to  say,  is  a  certain  sensational 


IDEALISM  183 

clot.  Burn  the  object,  and  it  exists  no  more.  Then  among 
the  sensational  sequence,  that  particular  grouping  will  no 
more  be  experienced.  But  this  is  not  yet  the  end  of  the 
matter.  It  is  many  years  since  I  was  last  in  Cape  Town. 
The  particular  clot  of  sensations  which  I  call  Cape  Town 
never  enters  into  my  sensational  sequence  at  the  present 
time.  Do  I  then  infer  that  Cape  Town  no  longer  exists  ? 
Not  in  the  least ;  for  although  those  particular  Cape  Town 
sensations  do  not  at  present  occur,  they  are  in  association 
with  other  sensations  which  lead  to  the  conviction  that  the 
sensational  sequence  might  hereafter  turn  in  such  a  direction 
as  to  bring  about  their  repetition.  In  the  case  of  the  burnt 
object,  on  the  other  hand,  the  associations  indicate  that, 
however  the  sensational  sequence  may  hereafter  flow,  that 
particular  clot  will  never  again  form  any  part  of  it.  Exist- 
ence then  is  not  a  primordial  datum  of  consciousness  ;  it 
is  the  name  given  to  a  certain  type  of  association  sub- 
sisting among  sensations.  Now  to  revert  to  the  critic's 
question.  You  define  me  as  a  clot  of  sensation.  When 
you  die,  the  sensation  will  cease.  Shall  I  therefore  also 
cease  ? 

The  answer  is  in  the  negative.  You  will  no  more  cease  to 
exist  when  I  die,  than  Cape  Town  ceases  to  exist  when  I  am 
in  London.  It  is  true  that  when  I  die  the  sensational  current 
will  cease  running  ;  but  the  associations  of  your  clot  are  such 
as  to  convince  me  that  if  by  some  miracle  the  flow  were  to  be 
resumed,  that  clot  would  again,  if  the  flow  was  in  that  direc- 
tion, be  capable  of  entering  once  more  into  experience.  The  ^ 
question  of  real  existence  does  not  depend  on  whether  the 
sensational  flow  runs  in  this  or  that  direction.  It  depends 
only  on  whether,  if  it  ran  in  the  right  direction,  it  would 
experience  the  clot  in  question.  If  I  died,  my  sensational 
flow  would  not  run  in  your  direction  any  more — indeed  it 
would  not  run  at  all — but  if  it  did  run  in  your  direction, 
it  would  again  perceive  you. 

Still  the  critic  is  dissatisfied.     You  say  I  am  sensation; 


184    MODERN  SCIENCE  AND  MATERIALISM 

you  say  the  sensation  may  vanish,  and  yet  I  continue  to 
exist.  How  is  that  possible  ? 

Again  I  must  lay  stress  on  what  is  meant  by  "  existence." 
It  is  simply  a  certain  type  of  relation  or  association  among 
the  sensations  composing  a  clot.  When  I  say  this  object 
exists,  or  you  exist,  what  I  mean  is,  that  the  group  of  sensa- 
tions composing  the  object  or  composing  you  is  associated 
with  certain  sensations  which  we  call  the  idea  of  existence. 
If  the  object  ceases  to  exist,  the  sensations  composing  it 
become  dissociated  from  the  idea  of  existence  ;  there  is  a 
break-up  in  the  associations.  It  is  not  merely  that  the 
object  no  longer  appears  in  consciousness,  for  that,  as  I  have 
said,  is  characteristic  of  many  objects  which  do  exist :  it  is 
that  various  associations  of  the  object  with  the  notion  of 
existence  are  broken  up,  and  new  associations  formed  with 
the  notion  of  non-existence  or  destruction.  Now  you  ask, 
when  my  conscious  flow  ceases,  do  you,  the  critic,  cease  to 
exist  ?  And  the  reply  is  that  you  do  not,  because  there  has 
been  no  break-up  of  the  associations  holding  you  in  the 
sensational  sequence.  "  Your  existence  "  is  a  phrase  naming 
a  certain  set  of  relations  existing  in  the  sequence.  If  you 
died,  those  relations  would  be  changed,  and  I  should  no 
longer  look  upon  you  as  existing.  But  if  you  survive, 
the  relations  would  remain  unaltered,  even  though  conscious- 
ness did  not  run  in  your  direction  at  all,  even  though  it 
were  abruptly  to  terminate. 

This  point  will  be  further  elucidated  by  considering  the 
origin  of  the  differentiation  between  mind  and  matter.  If 
they  are  both  kinds  of  sensation — if,  as  James  puts  it,  they  are 
both  made  of  the  same  stuff,  how  comes  it  that  men  have 
always  looked  upon  them  as  being  so  widely  different  ? 
And  following  upon  this  question,  we  have  to  discuss  the 
origin  of  ideas  of  soul,  ghost,  spirit,  and  so  on. 

The  main  attributes  of  matter,  which  distinguish  it  from 
mind,  appear  to  be  firstly  its  hardness  and  resistance  to  touch 
or  pressure  (though  this  is  not  characteristic  of  matter  in  all 


IDEALISM  185 

its  forms),  and  secondly  its  occupancy  of  space.  We  are 
unable  to  think  of  matter  otherwise  than  as  existing  in  a 
particular  region  of  space.  I  have  already  indicated  some 
of  the  elements  in  the  associated  group  of  sensations  which 
go  to  make  up  our  idea  of  space.  A  material  object,  then,  is 
a  combination  of  sensations  in  which  the  spatial  sensations 
form  one  of  the  component  parts.  But,  as  I  began  by  insist- 
ing, the  primary  distinction  of  matter  is  in  the  close  and 
indissoluble  association  existing  between  its  component 
qualities ;  and  my  present  purpose  is  to  show  that  it  is 
just  this  indissoluble  association  which  is  the  sole  point  of 
differentiation  between  matter  and  mind,  between  object  and 
subject. 

But,  I  shall  be  reminded,  there  is  surely  a  further  pro- 
found distinction.  Matter  is  permanent,  while  sensations 
are  ephemeral.  Matter  is,  as  Mill  defined  it,  "  a  permanent 
possibility  of  sensation."  Mind  is  a  procession  of  sensations 
without  any  permanence  at  all.  This  is  true,  but  the  case 
is  covered  by  my  definition  of  matter  as  closely-associated 
sensation.  I  see  before  me  a  table.  The  bald  sensations 
which  I  experience  are  simply  a  visual  arrangement  of  colour 
and  shade.  If  these  visual  impressions  ended  there,  and 
called  up  no  further  ideas  of  any  kind,  we  should  say  that 
the  experience  was  subjective.  But  in  point  of  fact  that  visual 
arrangement  of  colour  and  shade  irresistibly  suggests  solidity, 
distance,  hardness,  resistance,  utility,  the  name  "  table,"  and 
innumerable  other  qualities.  So  closely  is  the  visual  impres- 
sion associated  with  the  others,  that  it  is  impossible  to 
imagine  them  dissociated.  I  cannot  imagine  that  if  I 
walked  up  to  that  table  and  rapped  it,  I  should  find  no 
resistance  to  my  knuckles.  Yet  if  it  did  so  turn  out,  I  should 
promptly  set  down  my  visual  impression  as  a  mental  halluci- 
nation. The  sole  difference  between  the  two  experiences,  is 
that  in  the  one  the  visual  impression  is  associated  in  experi- 
ence with  other  sensations  (when  it  is  termed  matter),  and 
that  in  the  other  it  is  not  associated  with  other  sensations, 


186    MODERN  SCIENCE  AND  MATERIALISM 

but  is  free  and  unattached  (when  it  is  termed  mind).  The 
permanency  of  matter  consists  in  this  :  that  when  a  sensation 
arises  which  recalls  a  previous  sensation  associated  with 
a  number  of  others,  the  new  sensation  will  similarly  become 
associated  with  those  others.  To  revert  to  my  table.  The 
next  time  I  see  it  my  visual  impressions  will  be  such  as 
to  recall  my  present  and  previous  visual  impressions.  But 
these  are  associated  with  hardness,  solidity,  and  the  rest.  My 
next  visual  impression  of  the  table  will  therefore  be  similarly 
associated  with  these  qualities.  It  will  suggest  matter  and 
permanency. 

How  do  such  associations  come  to  be  established  ?  Suppos- 
ing the  mind  to  start  development  from  a  condition  of 
complete  tabula  rasa,  or,  as  I  prefer  to  put  it,  suppose  the 
sensations  experienced  to  start  in  a  condition  of  complete 
fluidity,  each  one  isolated  and  disconnected  with  any  other, 
associated  aggregates  soon  begin  to  be  formed  and  crystallize 
out.  Visual  sensations  of  a  particular  kind  are  so  frequently 
accompanied  by  tactual  sensations  of  a  certain  kind,  that  in 
future  those  visual  sensations  call  up  a  faint  form  of  those 
tactual  sensations  of  their  own  accord.  A  further  point  to 
be  noticed  is  that  certain  types  of  sensation  enter  into 
associative  bonds  much  less  easily  than  certain  other  types. 
In  general,  the  intense  sensations  which  are  called  emotions 
have  little  associative  capacity.  Take  the  example  of  a  tiger 
about  to  spring.  The  sensations  experienced  are,  in  the  first 
place,  visual :  yellow  stripes,  snarling  jaws,  and  so  on.  These 
suggest  irresistibly  the  idea  of  solidity  and  the  other  material 
attributes ;  they  suggest  the  name  of  tiger ;  and  among  other 
sensations  likely  to  be  called  up  is  what  we  call  the  emotion 
of  fear.  But  this  by  no  means  necessarily  enters  the  associative 
group  which  holds  attention  at  the  moment.  On  the  contrary, 
fear  may  be  completely  absent — the  attention  may  be  consumed 
wholly  in  taking  measures  to  escape  from  or  to  kill  the  animal ; 
or  it  is  even  theoretically  possible  that  one  may  have  had 
enough  of  life,  and  welcome  the  tiger  as  a  convenient  way  of 


IDEALISM  187 

getting  released  from  it.  What  I  mean  is  that  the  emotional 
element  hangs  very  loosely  on  to  the  group  of  sensations,  sug- 
gesting a  material  object.  The  visual  impression  necessarily 
gives  the  idea  of  a  material  object,  but  does  not  produce  an 
emotion  of  an  equivalent  stability  or  inevitableness.  The 
emotions  aroused  may  be  very  variable  with  different  states  of 
the  subject,  or  there  may  be  no  emotion  at  all.  And  hence  we 
speak  as  though  the  emotion  were  a  manifestation  of  the 
mind,  whereas  the  yellow  stripes,  etc.,  are  manifestations  of 
the  object.  Their  basis  in  experience  is  all  the  same ;  they 
are  equally  empirical  events ;  they  are  equally  cerebral 
neuroses.  It  is  the  fact  that  the  one  enters  into  close  associa- 
tions while  the  other  does  not,  that  causes  us  to  rank  them 
respectively  as  objective  and  subjective.  Emotions  in  general 
are  readily  dissociable,  and  in  this  respect  differ  profoundly 
from  the  sense-impressions,  which  in  strict  psychological 
language  are  alone  called  sensations. 

It  is  thus  that  we  arrive  at  the  distinction  between  mind  or 
spirit  and  matter.  The  former  is  the  free  and  unattached 
portion  of  experience ;  the  latter  is  the  associated  or  clotted 
portion.  The  former  is  the  basis  from  which  experience 
commences ;  the  latter  is  the  product  of  knowledge  or 
acquirement.  When  sensations  which  are  habitually  in 
association  with  other  sensations  occur  without  their  customary 
correlates,  we  get  the  idea  of  a  ghost.  If,  for  instance,  the 
visual  sensation  of  a  human  form  occurs,  and  no  corresponding 
sensation  of  resistance  or  solidity  can  be  obtained,  the 
primary  impulse  is  to  affirm  that  we  are  in  the  presence  of 
a  spirit.  Or  if  certain  visual  sensations  of  colour,  etc., 
suggesting  a  table  or  a  man,  are  not  associated  with  the  sen- 
sation of  opacity,  which  has  previously  invariably  accompanied 
them,  we  again  get  the  stock  conception  of  a  ghost :  a  form 
suggesting  materiality,  but  a  transparency  which  is  never 
found  with  that  particular  class  of  material  object.  Further, 
when  sounds,  as  of  chains  rattling,  emanate  from  a  spot  where 
no  visual  impressions  are  experienced,  we  again  affirm  that  a 


188    MODERN  SCIENCE  AND  MATERIALISM 

spirit  is  in  evidence.  For  sounds  are  exclusively  associated  in 
experience  with  material  objects,  giving  visual  and  tactual 
impressions.  Where  sounds  occur  without  any  of  the  usual 
correlated  sensations,  spirituality  is  immediately  alleged. 
That  is  to  say,  as  soon  as  the  elements  composing  a  cloti  of 
sensations  or  a  material  object  are  broken  up  and  appear 
independently,  they  are  affirmed  to  be  psychical.  Materiality 
is  wholly  a  product  of  association. 

We  now  approach  the  most  difficult  part  of  our  subject, 
and  that  which  will  be  most  puzzling  to  the  lay  mind :  the 
relation  of  body  to  mind,  or,  in  our  new  terminology,  the 
relation  of  the  system  of  associated  sensations  to  the  reservoir 
of  free  sensations  from  which  that  system  developed.  Among 
the  material  objects  which  after  some  months  of  life  form  a 
part  of  the  baby's  experience,  one  begins  to  stand  out  as  being 
unusually  ubiquitous.  Whereas  other  material  objects  come 
and  go,  there  is  one  from  which  experience  is  never  altogether 
free  for  long.  Moreover,  this  particular  object  exhibits  changes 
that  run  in  a  curiously  parallel  manner  with  the  general 
series  of  sensations.  In  short,  it  begins  to  be  discovered 
that  every  sensation  of  any  kind  seems  to  entail  some  activity 
in  the  object  noted.  The  object  mimics  the  sequences  of  the 
sensations.  For  every  alteration  of  sensation  experienced 
there  appears  to  take  place  some  corresponding  alteration  in 
the  relation  of  the  parts  of  the  object  in  question.  As  in  the 
case  of  other  objects,  this  one  becomes  associated  with  a  name 
in  the  course  of  education,  and  the  child  learns  to  know  its 
own  body,  as  being  an  object  more  nearly  allied  to  the  sensa- 
tional stream,  more  accurately  reflecting  its  changes,  than  any 
other  object. 

The  discovery  of  the  body  opens  the  way  to  a  new  series  of 
material  associations.  Hitherto  a  sensation  had  only  called 
up  the  other  sensations  with  which  it  had  been  immediately 
or  objectively  associated.  But  now  it  may  call  up  those  just 
as  before,  or,  on  the  other  hand,  it  may  call  up  the  sensations  of 
correlated  processes  in  that  exceptionally  ubiquitous  clot  now 


IDEALISM  189 

under  discussion.  The  visual  sensation  which  previously  gave 
rise  to  the  sensations  of  hardness,  etc.,  in  a  table,  may  now 
give  rise  to  the  same  sensations,  or  it  may  give  rise  to  sensa- 
tions of  the  bodily  changes,  ocular  adjustment,  etc.,  which 
run  parallel  to  the  original  sensation.  In  short,  to  every 
experience  there  are  now  two  routes  of  possible  association. 
Every  sensation  has  a  dual  attachment :  on  the  one  hand, 
with  the  other  sensations  experienced  in  contiguity  with  it, 
on  the  other  hand,  with  the  particular  clot  which  now  begins 
to  stand  out  vividly  from  the  rest.  These  associations  are 
what  we  know  as  objective  and  subjective,  and  the  clot  in 
question  comes  to  be  designated  by  the  pronoun  "  I." 

The  learning  of  science  quickly  brings  more  information  as 
to  the  nature  of  the  body,  that  is  to  say,  adds  to  the  number 
of  the  associations  which  that  particular  clot  represents. 
Speaking  of  it  now  in  our  ordinary  materialistic  language,  it 
is  found,  firstly,  that  sensation  is  not  a  product  of  the  body  as 
a  whole,  but  of  the  nervous  system,  and  secondly,  that  it  is 
not  a  product  of  the  nervous  system  as  a  whole,  but  of  certain 
parts  of  the  cerebral  cortex.  It  is  found  that  every  kind  of 
sensation  is  invariably  accompanied  by  certain  physico- 
chemical  processes,  still  not  understood,  in  a  limited  portion 
of  the  cerebral  cortex,  and  the  question  arises  as  to  the  relation 
of  these  processes  to  the  sensations  themselves  which 
accompany  them. 

From  our  present  point  of  view,  the  question  begins 
to  resolve  itself.  Supposing  physiology  had  reached  a  point 
at  which  it  could  say  that  the  sensation  of  redness,  for 
instance,  is  associated  with  such  and  such  physico-chemical 
processes  taking  place  in  such  and  such  neural  cells,  then 
we  should  know  as  much  about  the  sensation  as  was  possible 
on  the  subjective  side.  On  the  objective  side,  we  know 
about  the  colour  red  all  that  physics  has  to  tell  us — that 
it  consists  of  aethereal  waves  of  specific  length,  and  so  on. 
By  saying  that,  we  mean  that  the  sensation  of  redness 
has  been  by  scientific  exploration  indissolubly  associated 


190    MODERN  SCIENCE  AND  MATERIALISM 

in  educated  experience  with  the  sensations  imagined  from 
undulations  of  the  aether.  In  a  sense  we  may  affirm  that  the 
red  colour  is  the  undulations  of  named  wave-length. 

So  on  the  subjective  side,  physiology  ends  by  establishing 
an  indissoluble  association  in  educated  experience  between 
the  sensation  of  redness  and  the  sensations  derived  from 
witnessing  some  specific  neural  activity.  In  the  same  sense 
as  before,  it  would  even  be  correct  to  affirm  that  the 
sensation  of  redness  is  the  neural  activity  in  question.  But 
it  is  probably  advisable  to  avoid  the  use  of  words  expressing 
identity,  on  account  of  the  verbal  ambiguity  which  is  carried 
by  all  such  words.  The  facts  before  us  are  these:  (1) 
a  sensation  of  redness,  supposed  to  be  primary ;  (2)  the 
sensations  which  would  be  derived  from  sethereal  undulations 
of  specific  wave-length,  could  they  be  magnified  or  otherwise 
rendered  perceptible  ;  (3)  the  sensations  which  would  be 
derived  from  a  specific  type  of  neural  activity  taking  place 
in  specific  cells,  could  such  neural  activity  be  rendered 
perceptible.  The  relation  of  (1)  to  (2)  is  the  same  as  the 
-relation  of  (1)  to  (3).  The  physicist  affirms  that  the  redness 
is  indissolubly  united  with  certain  physical  events,  and 
he  may  even  say  that  the  one  is  the  other.  The  physiologist 
affirms  that  redness  is  indissolubly  united  with  certain  neural 
events,  and  he  too  may  affirm  that  the  one  is  the  other. 
But  in  either  case,  the  sum-total  of  our  knowledge  is  that 
certain  sensations  are  associated  with  one  another  to  a 
known  extent. 

In  so  far  as  the  exposition  has  proceeded  in  the  course 
of  the  present  chapter,  we  appear  to  have  reached  a  position 
of  absolute  idealism,  in  contrast  to  the  materialism  yielded 
by  the  studies  of  the  various  sciences  in  previous  chapters. 
It  is  nevertheless  a  position  entirely  compatible  with 
materialism  in  its  most  extreme  forms.  The  fallacy  which 
almost  universally  follows  in  the  wake  of  idealism  consists  in 
supposing  that  that  doctrine  denies  the  reality  of  matter, 
or  expresses  matter  in  terms  of  mind.  Let  me  repeat  again, 


IDEALISM  191 

therefore,  that  the  doctrine  which  I  have  adumbrated,  if 
rightly  understood,  does  not  in  the  slightest  degree  diminish 
a  belief  in  the  reality  of  matter ;  and  that  any  one  who  holds 
this  doctrine  is  committed  to  the  view  that  matter  is  just 
the  hard,  resistant,  solid  reality  that  it  appears  to  be  to  the 
the  most  abandoned  upholder  of  "  common-sense."  All  I 
have  said  is  that  matter  is  a  certain  kind  of  experience,  and 
this  no  one  denies — that  the  hardness,  resistance,  solidity, 
are  the  elements  of  the  experience.  But  in  saying  that 
matter  is  experience,  and  its  qualities  the  elementary  units  of 
the  experience,  I  am  infinitely  distant  from  affirming  that  it 
is  unreal.  Since  the  experience  is  real,  the  matter  is  also 
real.  I  have  not  done  as  is  commonly  done  by  idealists — I 
have  not  expressed  matter  in  terms  of  mind,  for  that,  indeed, 
would  imply  that  the  qualities  of  matter  are  psychical  images, 
caused  by  some  external  reality  of  unknowable  character. 
That  is  a  spiritualistic  doctrine,  to  which  I  am  utterly 
opposed.  So  far  from  my  beliefs  is  that  view  that  I  am 
now  about  to  deny  altogether  the  existence  of  any  psychical 
entity  to  be  called  mind,  apart  from  the  neural  processes 
which  are  supposed  to  accompany  the  workings  of  that 
entity.  I  am  about  to  argue  that  the  only  possible  meaning 
to  be  given  to  the  name  "  mind  "  is  the  sum-total  of  those 
material  neural  processes,  and  that  they  are  not  accompanied 
by  a  shadowy  entity,  meaningless  and  powerless,  as  assumed 
in  current  physiological  discussions. 

We  reached  the  conclusion  in  a  previous  chapter  that  the 
bodily  organism  is  a  complex  machine.  We  found  that 
all  its  processes  and  activities  are  attributable  to  physico- 
chemical  forces,  identical  with  those  which  are  recognized 
in  the  inorganic  realm.  We  learnt  that  there  is  no  "vital 
force"  or  other  spiritual  interference  with  the  normal 
physical  sequences.  If,  then,  there  be  a  mind,  it  is  reduced 
to  the  function  of  inertly  and  uselessly  accompanying 
the  activities  of  certain  neural  elements.  This  is  the 
doctrine  of  epiphenomenalism,  and  it  is  the  last  word 


192    MODERN  SCIENCE  AND  MATERIALISM 

possible  to  one  who  accepts  the  duality  of  mind  and  matter. 
It  is  a  theory  which  on  the  face  of  it  is  devoid  of  verisimi- 
litude. What  can  be  the  use  of  such  a  shadowy  and 
inefficient  entity  ?  What  parallel  can  be  found  in  Nature  for* 
the  existence  of  so  gratuitous  a  superfluity  ?  Moreover, 
what  mechanism,  conceivable  or  inconceivable,  could  cause  it 
thus  to  shadow  neural  processes,  which  ex  hypothesi  do  not 
produce  it  ?  If  one  such  mental  state  is  the  cause  of  the 
next,  how  does  it  happen  that  it  causes  the  one  which 
is  necessary  to  accompany  the  actual  neural  process  at 
the  moment  ?  Epiphenomenalism  involves  us  in  a  pre- 
established  harmony  that  is  profoundly  opposed  to  the 
scientific  spirit  of  the  twentieth  century.  The  problem, 
however,  is  not  one  that  need  be  discussed  on  the  grounds  of 
a  priori  probability.  It  is  a  theory  that  may  be  rigidly 
refuted,  and  to  that  task  I  now  turn. 

It  is  a  part  of  the  doctrine  of  epiphenomenalism  that 
a  man  would  to  all  external  appearance  be  precisely  the 
same  whether  he  was  possessed  of  his  epiphenomenal  mind 
or  not.  Conduct,  action,  expression,  would  not  in  the 
slightest  extent  be  affected  were  he  completely  devoid 
of  mind  and  consciousness  ;  for  all  these  things  depend  upon 
material  sequences  alone.  Men  are  puppets  or  automata, 
and  we  have  no  further  grounds  for  supposing  them  to  have 
minds  than  the  fact  that  we  know  we  have  a  mind  ourselves, 
and  the  argument  by  analogy  from  ourselves  to  them.  But 
arguments  from  analogy  are  notoriously  insecure,  and  it 
seems,  therefore,  to  be  quite  within  the  bounds  of  possibility 
to  the  epiphenomenalist  that  some  or  all  other  men  may  be 
mindless  syntheses  of  matter.  Descartes  did,  indeed,  affirm 
this  very  thing  of  lower  animals. 

Now  let  us  assume  that  such  a  man  actually  exists,  or, 
if  you  prefer,  let  us  assume  that  physical  chemistry  has 
advanced  to  such  a  pitch  that  a  man  may  be  synthetized  in 
the  laboratory,  starting  from  the  elements,  carbon,  nitrogen, 
etc.,  of  which  protoplasm  is  composed.  Let  us  assume  in  any 


IDEALISM  193 

case  a  u  synthetic  man "  without  a  mind,  yet  indistin- 
guishable by  the  epiphenomerialist  hypothesis  from  another 
man  identically  constituted  materially  but  having  a  mind. 
Ask  the  synthetic  man  whether  he  has  a  mind.  What  will 
he  say  ?  Inevitably  he  will  say  yes.  For  he  must  say  the 
same  thing  as  the  man,  identically  made,  who  lias  a  mind. 
Otherwise  the  same  question  would  set  up  different  responses 
in  the  nervous  systems  of  the  two,  and  that  is  by  hypothesis 
impossible.  The  sound  of  the  words  "  have  you  a  mind  ? " 
entering  the  ears  of  the  synthetic  man  sets  up  highly  com- 
plex cerebral  associations  (which  we  call  grasping  their 
meaning) ;  these  associations  will,  after  a  short  time,  culmi- 
nate in  nervous  currents  to  the  tongue,  lips  and  larynx, 
which  will  be  moved  in  such  a  way  as  to  produce  an  audible 
and  intelligent  answer.  Now  this  answer  must  be  the  same 
in  the  case  of  the  man  who  has  a  mind  as  in  the  case  of 
the  mindless  man,  since  their  nervous  systems  are  the 
same.  If  there  was  a  different  vocal  response  to  an  identical 
aural  stimulus,  then  there  must  in  one  of  them  have 
been  some  external  interference  with  the  physico-chemical 
sequences.  Mind  must  have  broken  through  the  chain  of 
physical  causality,  and  that  is  contrary  to  hypothesis. 

What  can  the  epiphenomenalist  say  ?  That  the  mindless 
man  is  a  liar,  to  say  he  has  a  mind  ?  That  will  not  do,  for  if 
the  two  men  are  objectively  identical  one  cannot  be  a  liar, 
and  the  other  not ;  one  engaged  in  deceit,  while  the  other 
speaks  the  truth.  The  epiphenomenalist  is  thrown  back,  there- 
fore, on  the  assumption  that  the  mindless  man  has  made  a 
mistake  ;  that  he  thinks  he  has  a  mind,  but  really  has  not 
one ;  that  his  nervous  constitution  is  such  as  to  impel  him  to 
the  conviction  that  he  has  a  mind  when  he  really  has  not, 
to  lead  him  to  talk  upon  psychical  phenomena  and  their 
differences  from  matter,  and  in  general  to  behave  exactly  as 
if  he  knew  all  about  mind  and  matter,  had  considered  the 
subject  of  their  relationship,  etc. 

The  example  shows,  furthermore,  that  the  condition  of 
o 


194    MODERN  SCIENCE  AND  MATERIALISM 

"knowing  one  has  a  mind"  is  a  condition  which  can  be 
stated  and  accounted  for  in  rigidly  materialistic  terms. 
When  the  epiphenomenalist  himself  asserts  that  he  has  a 
mind,  the  movements  of  his  vocal  cords  by  which  he  makes 
that  pronouncement  are  by  his  own  theory  led  up  to  by  a 
chain  of  purely  material  sequences.  He  would  make  just  the 
same  pronouncement  if  he  had  no  mind  at  all.  His  claim  to 
possess  a  mind,  therefore,  is  wholly  irrelevant  to  the  real 
question  whether  he  actually  has  a  mind  or  not.  The  events 
that  make  him  say  he  has  a  mind  are  not  the  actual  pos- 
session of  a  mind,  but  those  cerebral  processes  which,  in 
epiphenomenalist  language,  are  said  to  underlie  states  of 
consciousness.  It  is  the  cerebral  processes  alone  which  make 
him  speak,  and  his  utterance,  his  belief  in  a  mind,  furnish 
testimony  alone  to  the  existence  of  those  cerebral  processes. 
Were  the  mind  truly  able  to  compel  a  belief  and  an 
announcement  of  its  own  existence,  it  could  only  be  by 
breaking  through  the  chain  of  material  bodily  sequences, 
and  this  is  a  vitalistic  supposition  that  is  ruled  out  by 
physiology.  The  belief  in  the  possession  of  a  mind  is  a 
cerebral  condition,  due,  not  to  the  actual  possession  of  a 
mind,  but  to  definite  pre-existing  cerebral  conditions  on  the 
same  material  plane. 

I  do  not  see  how  epiphenomenalism  could  be  much  more 
effectively  refuted.  Yet  it  is  the  only  respectable  dualistic 
theory  that  is  compatible  with  physiological  mechanism. 
Let  me  recapitulate  for  a  moment  the  facts,  now  before  us, 
upon  which  we  have  to  establish  a  theory  of  the  relationship 
of  mind  and  body. 

Physiology  has  shown  that  bodily  activity  of  every  kind  is 
a  product  of  purely  material  sequences,  into  the  course  of 
which  there  is  no  irruption  of  any  spiritualistic  factor.  On 
the  dualistic  theory,  that  doctrine  is  excessively  difficult  to 
understand.  You  move  your  arm  by  an  act  of  will,  or  what 
seems  to  be  a  non-material  cause,  and  yet  it  is  conclusively 
established  that  the  movement  of  the  arm  is  due  to  definite 


IDEALISM  195 

material  changes  occurring  in  the  brain,  and  caused  by  the 
fixed  laws  of  physics  and  chemistry  in  the  most  determinist 
fashion,  Now,  anchoring  ourselves  firmly  to  that  fact,  we 
are  confronted  with  the  problem  of  where  to  put  the  mind. 
For  every  mental  state  there  is  some  corresponding  cerebral 
state ;  the  one  appears  to  be  the  exact  counterpart  of  the 
other  down  to  the  smallest  discoverable  particular.  Now  on 
the  dualistic  assumption,  there  is  only  one  possible  hypo- 
thesis, namely,  that  of  epiphenomenalism.  Or,  rather,  it  is 
incorrect  to  call  it  an  hypothesis  ;  for  if  there  are  two  things, 
mind  and  body,  epiphenomenalism  is  no  more  than  a  state- 
ment of  the  facts  established  by  physiology  and  psychology. 
Dualistic  physiologists,  therefore,  are  practically  forced  to 
accept  it.  Yet,  as  I  have  shown,  it  is  utterly  untenable 
when  properly  thought  out. 

We  are  faced,  therefore,  by  two  possible  alternatives  :  (1)  to 
abandon  mechanism,  (2)  to  abandon  dualism.  Now  mechanism 
is  a  physiological  theory  which  is  proved.  We  must  hold  fast 
to  it  therefore  at  any  expense  to  our  metaphysical  precon- 
ceptions. The  only  remaining  alternative,  then,  is  the 
abandonment  of  dualism.  We  must  affirm  that  there  is  no 
thin  shadow  accompanying  cerebral  processes  as  alleged ;  that 
there  are  not  two  things,  mind  and  body,  fundamentally 
distinct.  We  must,  in  short,  affirm  that  the  mind  is  the 
cerebral  processes  themselves,  not  an  imaginary  accompaniment 
of  them  •  and  this,  it  will  be  noticed,  is  precisely  the 
conclusion  at  which  we  arrived  by  different  arguments  in  an 
earlier  part  of  the  present  chapter.  When  we  recollect  that 
matter  is  but  one  form  of  experience,  while  mental  manifesta- 
tions are  another  similar  form ;  when  we  recollect  that 
elementary  experiences  may  be  associated  into  larger  groups, 
we  shall  scarcely  have  greater  difficulty  in  understanding  how 
a  sensation  can  be  identified  with  a  cerebral  process  than 
we  have  in  understanding  how,  for  instance,  redness  and 
hardness  can  be  identified  as  properties  of  one  material 
object. 


196    MODERN  SCIENCE  AND  MATERIALISM 

I  have  said  that  mind  is  not  an  independent  existence, 
but  that  it  is  a  name  for  the  sum-total  of  certain  kinds  of 
nervous  or  cerebral  processes,  and  that  it  is  therefore  to 
be  identified  with  phenomena  of  a  material  order.  The 
difficulty  of  grasping  this  proposition  will  be  very  largely 
mitigated  by  the  fact  that  there  exists  a  phenomenon  from 
the  inorganic  world  which  furnishes  a  remarkably  true  and 
precise  analogy  to  this  strange  product  of  the  organic  world. 
The  phenomenon  to  which  I  refer  is  the  phenomenon  of  fire. 
In  very  early  Greek  philosophy,  the  Universe  was  believed  to 
consist  of  earth,  air,  fire,  and  water.  Fire  was  held  to  be  a 
distinct  entity  on  a  par  with  the  other  three.  We  now  know 
that  it  is  not  itself  an  entity  of  any  kind,  but  is  a  manifesta- 
tion of  a  certain  chemical  process,  as  for  instance,  the  oxida- 
tion of  carbon,  in  the  course  of  which  the  carbon  particles 
give  forth  light  and  heat.  There  is  nothing  whatever  present 
in  a  flame  except  these  molecules  undergoing  chemical  change  ; 
yet,  to  an  uneducated  eye,  the  flame  seems  to  be  a  distinct 
entity,  differing  altogether  from  a  mere  collection  of  chemically 
active  material  particles. 

We  may  interpret  the  existence  of  mind  in  a  precisely 
analogous  manner.  All  that  really  exists  is  the  material 
particles  of  the  substance  of  the  nervous  system.  When 
these  particles  enter  upon  a  certain  kind  of  chemical  activity, 
the  effect  is  to  suggest  the  existence  of  some  new  kind  of 
elusive 'non-material  entity  called  mind.  But  this  entity  has 
no  more  real  existence  than  has  fire.  In  each  case  we  have 
to  do  exclusively  with  molecules  undergoing  disintegration 
or  combination.  This  chemical  activity  suffices  in  itself  to 
account  for  the  whole  of  the  phenomena  flowing  from  the 
centre  of  activity,  and  the  belief  in  any  additional 
independent  entity  is  a  fallacy  which  itself  can  be  expressed 
and  explained  in  physico-chemical  terms.  The  flames  of  a 
fire  flash  out  swiftly  in  all  directions  and  vanish  again,  to 
reappear  instantly  in  a  closely  similar  form.  So,  too,  the 
ideation  or  emotion  of  the  individual  may  open  up  new 


IDEALISM  197 

avenues  of  mind  for  a  brief  moment,  as  they  travel  on  to  a 
new  position.  In  each  case  the  fluctuations  of  form  are  due 
to  the  constantly  changing  area  of  chemical  activity;  and 
just  as  the  fire  maintains  for  short  periods  a  relative  constancy 
of  size  and  shape,  so  the  mental  content  of  an  individual  is 
apt  to  remain  for  a  time  at  about  the  same  value  of  intensity, 
and  fastened  to  the  same  subjects  of  attention.  At  times 
the  fire  burns  low ;  at  other  times  it  bursts  forth  into 
exuberant  activity.  The  accuracy  of  the  analogy  is  due  to 
the  fact  that  both  phenomena  are  based  upon  the  same 
foundation  ;  the  one  is  a  manifestation  from  inorganic  matter, 
while  the  other  is  a  manifestation  from  organic  matter,  and 
therefore  immeasurably  more  complex  as  to  its  chemistry. 

When  once  we  have  got  over  the  shock  which  monism 
carries  to  those  accustomed  to  think  in  dualistic  terms,  we 
find  that  the  great  majority  of  the  difficulties  of  metaphysics 
fall  away.  By  an  act  of  will  I  raise  my  arm.  The  plain 
man  insists  that  his  will  did  it ;  the  physiologist  knows  that 
it  was  physico-chemical  processes  in  the  brain.  The  dilemma 
is  at  once  overcome  when  the  philosopher  points  out  that 
the  will  is  the  physico-chemical  processes,  and  that  they  both 
mean  the  same  thing.  The  whole  controversy  of  free-will  and 
determinism  is  resolved  by  the  discovery  that  each  side  means 
exactly  the  same  thing,  the  only  difference  being  in  the  terms 
used.  The  difficulty  of  the  epiphenomenalist  is  also  solved. 
He  says  he  has  a  mind.  What  makes  him  say  so  is  not  a 
transcendental  "  knowledge  of  having  mind,1'  but  a  certain 
cerebral  state.  When  we  have  affirmed  the  absolute  identity 
of  that  knowledge  with  that  cerebral  state,  all  difficulties 
vanish.  The  mind  is  the  sum-total  of  cerebral  conditions. 
He  says  he  has  a  mind;  it  is  the  existence  of  the  cerebral 
conditions  which  cause  him  to  say  so.  He  says  he  has  a  mind 
because  he  has  cerebral  conditions,  and  his  remark  is  true 
and  intelligible  only  on  the  one  hypothesis  that  the  mind  is 
the  cerebral  conditions. 

A  further  difficulty  that  is  abolished  by  monism  is  that  of 


198    MODERN  SCIENCE  AND  MATERIALISM 

the  unity  and  personality  of  mind.  We  feel  that  our 
consciousness  is  not  made  up  merely  of  a  succession  of 
discrete  elements,  but  that  these  are  bound  together  as 
properties  of  a  single  entity,  mind  or  soul.  This  unity  of 
consciousness  finds  its  exact  parallel  in  the  unity  of  the 
nervous  system.  I  have  already  pointed  out  that  neural 
activity  tends  at  any  moment  to  be  focussed  at  some 
particular  part  of  the  nervous  system.  The  focus  of  activity 
may  travel  from  one  part  to  another  of  the  nervous  system, 
but  activity  does  not  normally  extend  over  any  large  portion 
of  the  nervous  system  at  any  one  moment.  The  region  of 
the  nervous  system  momentarily  illuminated  by  functional 
activity  corresponds  to  the  state  of  consciousness  momen- 
tarily experienced.  And  just  as  the  focus  of  activity  can 
travel  freely  from  one  part  of  the  nervous  system  to  another, 
but  can  never  travel  outside  the  nervous  system,  so  states  ot 
consciousness  can  follow  one  another  within  the  limits  of  the 
mind,  and  no  state  of  consciousness «can  be  experienced  which 
is  not  a  part  of  the  personal  and  individual  mind. 

Monism  again  resolves  the  great  biological  difficulty  as  to 
the  origin  of  consciousness.  The  biological  conclusions  as  to 
the  origin  of  life  are  to  the  effect  that  living  and  organic 
matter  was  developed  by  evolution  from  non-living  and 
inorganic  matter.  The  evolution  of  Man  from  unicellular 
parentage  is  a  fact.  There  is  little  or  no  reason 
to  doubt  that  his  unicellular  ancestor  was  evolved  just  as 
gradually  from  inorganic  matter.  Now,  says  the  dualist,  we 
know  that  the  man  has  a  mind.  It  follows,  therefore,  either 
that  inorganic  matter  has  a  psychical  accompaniment,  or 
else  that,  in  the  course  of  evolution,  there  was  a  sudden  leap  : 
mind  was  suddenly  intruded  at  some  period  of  Man^s  past 
history.  Neither  of  these  hypotheses  is  easy  to  entertain, 
or  perhaps  even  practicable  to  conceive.  The  doctrine  of 
monism,  with  its  assertion  that  there  are  not  two  ultimate 
things,  but  one,  causes  the  difficulty  to  vanish ;  for  there  is 
then  no  necessity  to  introduce  a  new  entity  at  any  period 


IDEALISM  199 

of  an  organism's  evolution.  According  to  our  theory,  a 
conscious  state  is  a  specific  neural  functioning.  If  there  is 
no  discontinuity  in  the  evolution  of  nervous  elements  from 
inorganic  matter,  there  is  then  no  discontinuity  in  the 
evolution  of  consciousness. 

We  are  introduced  furthermore  to  the  answers  required 
to  such  questions  as  "  Do  snails  feel  ? "  There  is  a  very 
common,  though  of  course  entirely  groundless,  superstition 
that  cold-blooded  animals  have  no  feeling ;  and  the  question 
how  far  the  lower  animals  have  sensation  is  important  for 
estimating  the  pain  which  may  be  inflicted  upon  them  by 
various  kinds  of  human  actions.  We  are  now  in  a  position 
to  answer  in  a  general  way  that  the  amount  of  feeling  is 
dependent  upon  the  extent  of  the  development  of  the  nervous 
system.  With  the  progress  of  physiological  psychology,  we 
shall,  no  doubt,  hereafter  be  able  to  give  a  much  more  specific 
reply.  We  have  up  to  now  hardly  yet  grasped  the  fact  that 
pain  is  a  mode  of  neural  functioning.  We  have  made 
scarcely  any  progress  with  the  question  as  to  what  mode. 
We  entertain  no  doubt  that  pain  is  some  entirely  specific 
physico-chemical  process.  When  we  know  the  exact  nature 
of  that  process,  and  when  we  know  also  the  exact  physico- 
chemical  constitution  of  an  animal,  we  shall  then  be  able  to 
say  from  observation  exactly  how  much  pain  it  is  susceptible 
of  feeling,  and  how  much  it  is  actually  feeling  at  any  given 
moment.  In  visualizing  the  physico-chemical  processes  at 
work,  we  shall  be  visualizing  the  very  pain  itself.  Let  me 
repeat  even  once  again  the  argument  by  which  so  apparently 
incongruous  a  doctrine  is  not  only  conceivable,  but  the  only 
conceivable  way  in  which  the  facts  can  be  interpreted. 

In  the  course  of  our  manifold  experiences,  one,  and 
unfortunately  a  common  one,  is  that  of  pain.  As  in  the 
developing  mind  association  begins  to  bind  together  the 
elements  of  experience,  we  arrive  at  the  conception  of  matter, 
or,  rather,  at  matter  itself.  Physics  adds  constantly  new 
elements  to  the  associated  group.  That  green  box  which  I 


200    MODERN  SCIENCE  AND  MATERIALISM 

see  before  me  consists,  according  to  the  physicist,  of  a  vast 
aggregate  of  discrete  molecules,  undergoing  vibration.  Each 
molecule  similarly  consists  of  a  little  group  of  atoms,  also 
vibrating.  The  atoms  in  turn  are  divisible  into  yet  smaller 
units.  Now  the  green  box  which  I  behold  has,  on  the  face  of 
it,  nothing  in  common  with  the  sensations  which  would  appear 
proper  to  a  vast  army  of  isolated  particles.  The  one  is  con- 
tinuous, the  other  discontinuous ;  the  one  is  motionless,  the 
other  is  in  rapid  motion  throughout  its  parts,  etc.  Yet  the 
sensation  yielded  by  the  one  is  now  associated  with  the 
potential  sensations  derivable  from  the  other,  so  that  we  say, 
in  perfect  confidence,  that  the  one  is  the  other.  In  just  the 
same  way  there  seems  to  be  no  similarity  between  the  sensa- 
tion of  pain  and  the  sensations  derived  from  observation, 
actual  or  potential,  of  the  physico-chemical  processes  which 
occur  in  nerve-cells.  Yet  the  two  are  associated  so  closely 
and  invariably,  that  we  are  compelled  to  affirm  in  the  same 
way  that  the  one  is  the  other. 

The  question,  then,  as  to  how  low  in  the  animal  scale  feeling 
is  experienced,  is  resolved  into  the  more  intelligible  question 
as  to  how  low  in  the  animal  scale  do  the  physico-chemical 
processes  take  place  which  we  identify  as  feeling.  That 
question  can  only  be  definitely  answered  when  it  is  definitely 
known  what  exactly  those  physico-chemical  processes  are. 
But,  in  the  meantime,  it  may  be  permissible  to  speculate ; 
and  the  most  attractive  speculation  certainly  seems  to  be  that 
feeling  is  contemporaneous  with  organization ;  that  the 
physico-chemical  processes,  though  reaching  their  highest 
activity  in  the  nervous  systems,  are  processes  which  occur  in 
a  more  primitive  manner  in  undifferentiated  protoplasm  itself. 

We  may,  for  a  moment,  profitably  compare  the  philo- 
sophical result  which  we  have  reached  with  the  structure  of 
the  nervous  system.  We  have  built  up  the  whole  of  mental 
life  from  elementary  sensations,  which  are  susceptible  of 
becoming  associated  more  or  less  closely  together.  Sensations 
are  the  only  fundamental  reality,  so  far  as  we  are  concerned, 


IDEALISM  201 

and  association  is  the  only  fundamental  process.  All  abstract 
ideas,  such  as  that  of  "existence,"  are  compounded  of  sensa- 
tions related  to  one  another  by  more  or  less  close  degrees 
of  association.  In  general,  for  instance,  "existence"  is  a 
property  of  an  object  connoting  the  liability  to  raise  certain 
sensations  under  certain  conditions.  It  is  resolved  ultimately 
into  an  anticipation  of  possible  visual,  tactual  or  other  sensa- 
tions ;  and  it  has  no  meaning  whatever  except  in  so  far  as  it 
may  be  expressed  in  terms  of  sensation.  I  say  "  in  general," 
because  the  word  "  existence,1'  like  all  words  in  common  use, 
has  no  clearly  defined  limitation  of  meaning,  but  is  used  in 
many  different  senses.  But  the  sense  in  which  I  have  taken 
it  is  the  only  one  that  has  any  interest  for  the  present 
discussion. 

It  is  their  failure  to  appreciate  this  circumstance  that  has 
caused  so  many  metaphysicians  to  embark  upon  the  solution 
of  false  and  unreal  problems,  such  problems  as :  Does  matter 
exist  ?  Do  other  men  exist  ?  Do  I  exist  ?  with  the  singu- 
larly unsatisfactory  replies  of  which  Descartes'  is  a  type : 
cogitOy  ergo  sum.  If  a  particular  group  of  sensations  contains 
among  them  the  sensations  connoted  by  existence,  then  that 
object  exists  (except  in  illusions,  where  the  component  sensa- 
tions are  linked  in  unusual  associations).  But  there  is  no 
metaphysical  problem  of  real  existence ;  for  the  whole  idea 
of  existence  is  phenomenal,  not  noumenal,  so  to  speak;  it 
depends  on  the  quality  of  the  association  between  sensations. 
But  a  still  more  dangerous  fallacy  is  that  which  deduces  from 
idealism  the  non-reality  of  matter.  Reality,  like  existence, 
is  not  a  property  of  so-called  "  noumena  "  ;  and  by  merely  in- 
cluding matter  and  mind  under  the  one  heading  "  experience," 
there  is  no  more  derogation  from  the  reality,  solidity,  ex- 
teriority of  matter,  than  there  is  from  the  essential  qualities 
of  mind.  Matter  is  real,  in  the  amplest  possible  sense  that 
can  be  applied  to  the  term  real.  It  requires  no  underlying 
basis  or  noumenon  to  support  its  claim  to  reality.  It  is  as 
real  as  anything  that  can  be  brought  within  our  under- 


r 


202    MODERN  SCIENCE  AND  MATERIALISM 

standing.  When  I  affirm  that  Esse  est  percipi,  I  am  not 
diminishing  the  reality  of  Esse  any  more  than,  when  I  affirm 
that  heat  is  motion,  I  diminish  the  reality  of  heat. 

The  synthesis  of  mind  from  simple  elements,  conjoined 
with  one  another  to  a  varying  extent,  has  its  exact  parallel 
in  the  structure  of  the  nervous  system.  For  the  nervous 
system  is  entirely  made  up  of  central  ganglionic  cells  on  the 
one  hand,  and  conducting  fibres  on  the  other  hand,  by 
which  cells  are  kept  in  association  with  one  another  through 
synapses.  We  must  suppose  that  in  the  theoretically  primi- 
tive condition,  where  the  sensations  are  entirely  dissociated, 
the  association  fibres  running  between  the  cortical  cells  are 
still  undeveloped,  or  the  synapses  impermeable.  Stimulus 
to  the  sense-organ  produces  activity  in  the  corresponding 
cortical  cells,  and  that  activity  is  sensation.  An  ocular 
stimulus  gives  rise  to  colour-sensations  in  a  certain  part 
of  the  brain.  A  tactual  stimulus  gives  rise  to  pressure- 
sensations  in  another  part.  But  there  is  no  high-road  of 
association  between  these  two  parts.  The  colour-sensation 
does  not  invoke  the  anticipation  of  tactual  sensation, 
and  there  is,  in  consequence,  no  conception  of  matter.  With 
progressive  development  the  paths  of  association  are  per- 
fected, and  considerable  areas  of  the  brain  come  to  function 
as  independent  units.  This  is  the  cerebral  origin  of  the  idea 
of  matter.  In  the  perception  of  a  material  object  two  things 
are  involved:  (1)  the  object  itself;  (2)  the  cerebral  activity 
set  up  by  stimulus  by  the  object  upon  the  sense-organs.  The 
first  is  the  associated  sum  of  sensations,  called  the  qualities 
of  the  object ;  the  second  is  the  consciousness  of  the  object ; 
and  it  is  this  duality  of  material  things  which  represents  the 
difference  between  the  psychical  and  the  physical. 

We  may  now  begin  to  perceive  how  it  is  that  science  is 
based  upon  materialism,  and  how  materialism  is  the  only 
possible  working  hypothesis  of  life.  The  psychological 
doctrine  of  association  shows  that  all  intellectual  operations, 
including  therein  all  scientific  theories,  proceed  by  bringing 


IDEALISM  203 

two  previously  isolated  factors  into  relation  with  one 
another.  I  will  take  an  instance  which  I  employed  in  a 
former  work.  Sir  Isaac  Newton  saw  an  apple  fall  to  the 
ground.  He  had  previously  been  reflecting  on  the  causes 
which  kept  the  planets  in  their  orbits.  The  discovery  of  the 
law  of  gravitation  took  place  when  these  two  widely  remote 
events  were  suddenly  brought  into  relation  with  one  another 
and  perceived  as  illustrations  of  a  single  principle. 
Observation  and  co-ordination  are  the  two  ultimate  factors 
of  science.  By  observation  new  properties  of  objects  are 
placed  on  record.  By  co-ordination  they  are  generalized, 
classified  and  brought  into  relation  with  the  previous  system 
of  knowledge.  Here  once  more  are  the  original  elements  ot 
mental  life  with  which  we  have  become  so  well  acquainted. 
New  sensations  are  brought  into  the  arena  of  attention  ;  this 
corresponds  to  observation.  New  associations  are  formed 
between  them  and  other  known  associated  sensations;  this 
corresponds  to  co-ordination.  The  most  abstruse  conceptions 
of  science  are  reached  by  precisely  the  same  methods  as 
those  by  which  the  conception  of  matter  is  reached  in  the 
mind  of  the  infant.  Sensations  compounded  are  the  basis 
of  matter.  A  scientific  theory  is  a  statement  of  some 
immensely  elaborate  association,  combining  perhaps  myriads 
of  isolated  observations.  The  discovery  of  matter  is  the 
foundation  of  science,  and  the  first  step  made  in  the  creation 
of  knowledge.  Sensations,  originally  free,  begin  to  hang 
together  in  little  groups.  Here  we  get  matter.  The  little 
groups  hang  together  in  larger  groups,  and  we  get  the 
beginnings  of  science.  The  larger  groups  hang  together,  and 
we  have  the  greatest  generalizations  of  science.  Some  dream 
of  a  time  when  these  larger  groups  will  be  compounded  and 
re-compounded  again  till  the  whole  of  sensible  phenomena 
are  brought  within  the  range  of  a  single  generalization : 
they  dream  of  a  total  unification  of  knowledge. 

However  that  may  be,  we  reach  the  conclusion  that  science 
is  a  statement   of  the  most  complex  and  elaborate  of  the 


204    MODERN  SCIENCE  AND  MATERIALISM 

associations  found  to  exist  among  the  various  items  of 
experience.  Matter  represents  the  most  elementary  and 
simple  of  all  the  associations  among  items  of  experience. 
Thus  science  must  of  necessity  rest  upon  matter.  Its  units 
are  the  little  groups  of  sensation  called  material  objects. 
The  relation  of  science  to  matter  is  identical  with  the 
relation  of  algebra  to  the  symbols  #,  «/,  z9  which  enter  its 
equations,  a?,  ?/,  and  z  stand  for  some  specific  arithmetical 
quantities,  just  as  the  material  object  "table"  stands  for 
specific  elementary  sensations.  Science,  if  removed  from 
its  material  basis,  and  compelled  to  start  from  primitive 
sensation,  would  resemble  a  mathematics  from  which  the 
symbols  of  algebra  and  the  calculus  were  excluded,  and 
which  had  to  work  in  arithmetical  figures  alone. 

The  question  whether  there  can  be  any  science  not  based 
upon  materialism,  or  contradictory  of  materialism,  receives  a 
negative  answer.  Science  is  the  product  of  a  materialistic, 
scheme  of  things,  and  rests  upon  matter,  as  physics  rests 
upon  the  conservation  of  energy.  Nor  is  there  anything 
very  dreadful  in  this  kind  of  materialism  ;  for  it  is  only 
a  name  for  the  way  in  which  sensations  hang  together. 
Knowledge  is  association.  Materialism  is  the  name  for  the 
great  scheme  of  associated  sensations  which  represents  all 
knowledge.  The  free,  unassociated  sensations  or  emotions 
which  have  hitherto  remained  outside  the  materialistic 
scheme,  have  at  the  same  time  remained  elementary  facts  of 
which  nothing  whatever  was  known.  The  only  hope  for 
knowledge  concerning  mental  states  is  to  bring  them  within 
the  scheme  of  materialism.  That,  happily,  is  now  on  the  way 
to  accomplishment.  The  identification  of  mental  states  with 
cerebral  states  brings  them  immediately  within  the  scope  o* 
the  "  laws  "  of  matter,  of  physics,  and  of  physiology.  The 
generalizations  and  principles  established  for  those  sciences 
can  now  be  made  available  to  furnish  information  concern- 
ing the  coexistences  and  sequences  among  mental  states. 
Nothing  any  longer  remains  outside  materialism,  which  now 


IDEALISM  205 

embraces  every  branch  of  physical  and  psychical  phenomena. 
Hence  it  is  that  the  man  of  science,  the  physiologist,  and 
even  the  psychologist,  may  speak  as  though  nothing  what- 
ever existed  but  matter.  Hence  it  is  that  mind,  as  apart 
from  matter,  has  been  banished  from  any  share  in  causality 
or  scientific  explanations.  Hence  it  is  that,  on  the  assump- 
tion of  matter  alone  without  mind,  the  psychologist  can 
analyze  the  motives  and  prophesy  the  actions  of  humanity. 

Such  being  our  conclusions  with  regard  to  materialism, 
what  is  to  be  said  of  the  numerous  systems  of  philosophy 
and  theology  that  have  from  time  to  time  been  built  up  ? 
In  general  they  attempt  to  explain  difficulties  and  furnish 
solutions  by  imagining  the  existence  of  fictitious  entities. 
In  the  case  of  religions,  this  statement  needs  no  illustration. 
The  various  systems  of  theology  proceed  on  the  assumption 
that  there  exist  a  god  or  gods  wholly  immaterial  in  character. 
A  ready-made  explanation  is  thus  at  hand  for  any  difficulties 
which  occur  as  to  relation  of  mind  and  body  or  any  other  of 
the  problems  of  philosophy.  It  is  needless  to  reopen  the 
great  conflict  of  the  nineteenth  century  between  science  and 
religion.  Little  interest  is  now  taken  in  the  question. 
The  vast  majority  of  thinkers  have  abandoned  any  attempt 
at  theological  explanations.  Theology  has  been  weighed 
in  the  balance  and  found  wanting. 

But  still  a  belief  in  spiritual  existences  of  various  kinds 
remains  tolerably  widespread,  though  much  less  firmly  estab- 
lished than  of  old.  Such  a  belief,  for  instance,  is  that  in 
souls,  which  even  now  finds  scientific  defenders  such  as  Dr. 
William  McDougall.  In  the  Middle  Ages  souls  were 
regarded  as  scarcely  less  material  than  the  bodies  to  which 
they  were  attached.  In  drawings  of  the  twelfth  century, 
for  instance,  the  soul  is  depicted  as  more  or  less  human  in 
form.  It  had  weight  and  could  be  balanced  in  scales.  It 
was,  and  indeed  remained  till  much  later,  liable  to  pain  from 
the  same  physical  causes,  such  as  fire,  that  produce  pain  in 
material  organisms.  Just  the  same  beliefs  are  found  among 


206    MODERN  SCIENCE  AND  MATERIALISM 

primitive  peoples  of  the  present  day.  They  leave  food 
beside  a  dead  man's  grave  for  the  soul  to  feed  upon.  They 
leave  holes  in  the  grave  for  the  soul  to  come  in  and  out,  or 
they  pile  mounds  over  it  to  keep  it  in.  In  more  advanced 
culture  the  materiality  of  the  alleged  soul  decreases.  It  is 
identified  in  a  vague  sort  of  way  with  the  breath ;  hence, 
indeed,  the  very  name  of  spirit,  from  the  Latin  for  breath. 
Still  later  it  was  divested  further  of  material  qualities.  It 
long  continued,  however,  to  retain  the  material  quality  of 
occupying  space,  and  numberless  speculations  were  indulged 
in  as  to  "  the  site  of  the  soul.1' 

Many  other  metaphysical  theories  proceed  on  similar  lines. 
Hans  Driesch,  for  instance,  proposed  to  explain  organic 
development  by  means  of  a  mysterious  thing  called  entelechy, 
aided  by  an  if  possible  more  mysterious  thing  called  psychoid. 
Others  invoke  "biotic  energy"  for  the  same  purpose. 
"  Noumena "  and  "  the  Absolute "  are  favourite  creations 
of  a  large  and  influential  school  of  metaphysicians.  In 
general  it  may  be  laid  down  that  the  creation  of  imaginary 
entities  is  a  tempting  method  of  "explanation"  which  is 
likely  to  continue  for  long  to  mislead  the  unwary. 

Now  it  is  characteristic  of  all  these  spiritual  entities  that 
they  can  only  be  conceived  by  attributing  to  them  material 
qualities,  and  that  as  soon  as  they  are  completely  deprived 
of  all  material  qualities  they  and  the  belief  in  them  promptly 
vanish.  For,  as  I  have  so  frequently  repeated  in  the  course 
of  this  chapter,  beliefs,  like  all  other  mental  states,  are  products 
of  sensation  and  association.  Where  there  is  no  sensation, 
either  real  or  imagined,  there  is  no  belief.  If  a  spirit  has 
neither  visibility,  nor  tangibility,  nor  divisibility,  nor  position 
in  space,  nor  any  other  property  whatever,  it  is  then  identical 
with  nothing.  To  conceive  it,  or  to  believe  in  it,  is  to 
materialize  it  to  some  extent.  It  is  imagined  as  having  a 
position  in  space,  or  some  vague  generalized  form  such  as 
the  spherical,  or  the  power  to  emit  light  or  sound,  or  to 
move  bodies,  or  some  other  purely  material  attribute.  In 


IDEALISM  207 

short,  spirit  cannot  be  conceived  off  the  material  plane.  The 
name  either  connotes  nothing,  or  it  connotes  some  material 
quality.  The  very  statement  that  it  exists  is  the  attribution 
to  it  of  a  purely  material  characteristic.  And  in  so  far  as 
it  possesses  material  characteristics,  it  is  included  within  the 
materialistic  scheme  of  natural  events. 

Spiritualism,  then,  has  to  be  condemned  root  and  branch. 
And  in  so  condemning  it,  1  would  include  under  it  various 
other  beliefs  not  usually  associated  with  it.  I  would  include, 
for  instance,  the  metaphysical  materialism  of  the  ancient 
Greeks.  For  their  materialism  was  very  different  from  ours. 
They  acquiesced  in  the  existence  of  souls,  and  differed  only 
from  the  spiritualists  in  affirming  that  souls  were  made  of 
matter.  That  they  were  philosophically  far  more  advanced 
than  their  spiritualistic  contemporaries  is  true;  for  their 
materialistic  outlook  anticipated  modern  views  in  a  very 
remarkable  manner.  But  scientific  materialism  of  the  present 
day  has  kept  their  general  point  of  view,  while  dropping 
their  metaphysics.  We  agree  with  Democritus  that  if  there 
were  a  second  entity  connected  with  the  body,  it  would 
necessarily  be  a  material  thing ;  but  we  deny  the  existence 
of  any  such  entity. 

The  question  of  the  origin  of  ideas  of  soul,  spirit,  etc., 
has  been  approached  both  from  the  psychological  and  the 
sociological  sides,  and  numerous  theories  have  been  suggested. 
There  is  no  occasion  here  to  enter  upon  so  controversial  a 
subject.  We  are  concerned,  not  with  the  origin  of  the  idea, 
but  with  the  fact  that  the  idea  is  a  superstition.  All  existences 
of  every  kind  form  part  of  the  materialistic  scheme  propounded 
by  physics,  and  the  assertion  that  there  are  existences  outside 
that  scheme  is  not  even  an  intelligible  statement:  it  is  a 
sentence  which  carries  no  correlate  in  the  realm  of  ideas.  It 
is  conceived  only  by  tacitly  supplying  the  material  attributes 
which  are  verbally  denied. 

Criticism  on  this  doctrine  usually  runs  on  the  lines  that 
it  is  a  "narrow"  and  "unsatisfying"  interpretation  of 


208    MODERN  SCIENCE  AND  MATERIALISM 

Nature;  that  by  bringing  everything  within  a  mechanical 
system,  we  knock  the  very  soul  out  of  life  and  Nature.  I 
am  little  interested  to  meet  this  criticism,  which,  indeed,  has 
no  reference  to  the  subject  of  the  present  work.  I  have  been 
endeavouring  to  show  that  the  doctrine  is  true ;  and  in  so 
far,  it  is  a  matter  of  indifference  to  me  whether  it  is  narrow 
and  unsatisfying  or  not.  That  is  a  question  of  altogether 
different  character,  to  be  argued  on  totally  different  principles. 
I  fail  to  see  the  slightest  grain  of  accuracy  in  the  criticism, 
however.  We  know  what  life  is,  with  its  art,  its  morality, 
its  beauty  and  ugliness,  its  goodness  and  badness.  All  these 
things  are  just  the  same  in  fact,  whatever  may  be  the  theories 
which  we  form  of  them.  Nature  is  just  the  same  Nature, 
whether  our  theories  of  it  are  materialistic  or  spiritualistic ; 
and  the  purpose  of  my  theory  is  not  to  satisfy  the  emotions 
but  to  state  the  truth.  There  are  a  certain  number  who 
used  to  think  that  Man  is  degraded  by  his  descent  from  apes. 
Why  they  should  think  so  is  a  puzzle  to  those  whose  minds 
are  philosophically  orientated,  for  the  nature  of  Man  is 
exactly  the  same  whatever  our  theory  may  be.  He  is  just 
the  same  man,  whether  he  is  descended  from  apes  or  gods. 
So,  too,  Nature  is  not  altered  a  particle  by  the  discovery 
that  it  is  organized  into  a  materialistic  scheme. 

Others,  again,  are  distressed  because  materialism  offers 
them  no  prospect  of  a  future  life.  This,  again,  if  it  is  a 
fault,  is  the  fault  of  Nature  and  not  of  the  philosopher  who 
describes  Nature.  But  there  seems  nothing  so  very  terrible 
about  it,  to  one  who  looks  at  the  facts  calmly.  The  emotion 
of  fear  of  death  has  been  developed  by  Natural  Selection ; 
for  without  it  no  advanced  species  could  continue  to  exist. 
Death  at  all  events  extinguishes  that  emotion  in  common 
with  the  rest.  But,  as  it  happens,  we  are  partially  dying 
from  the  day  we  were  born.  I  do  not  allude  to  the  fact 
that  the  matter  of  which  our  bodies  are  composed  is  con- 
tinually changing,  so  that  after  a  year  or  two  we  are 
composed  of  altogether  different  material  substance ;  I  refer 


IDEALISM  209 

more  to  mental  changes.  The  mind  which  we  possessed 
at  the  age  of  three  is  dead  and  gone ;  and  at  the  age  of 
seventy  a  man  bears  less  resemblance  to  himself  at  three 
than  he  does  to  other  men  of  seventy.  The  mind  has 
radically  changed,  the  body  is  entirely  different ;  the  child 
is  effectively  gone  as  much  as  if  it  was  dead.  In  the  words 
of  St.  Augustine :  Ecce  infantia  mea  olim  mortua  est  et  ego 
vivo.  Why  then  do  we  not  bemoan  the  spiritual  death  of 
our  childhood  as  much,  or  more,  than  we  do  the  anticipated 
death  of  old  age  ?  By  all  reasonable  standards,  the  loss  of 
youth  is  more  regrettable  than  the  loss  of  an  old  and  decrepit 
body  and  mind.  It  is,  on  the  whole,  true  that  youth  is  spent  in 
the  pursuit  of  pleasure,  while  old  age  is  spent  in  the  avoidance 
of  pain.  Yet  men  fear  far  more  the  ultimate  extinction  of 
life  than  they  do  the  onset  of  old  age.  And  the  reason  is 
plain :  that  Natural  Selection  has  developed  an  emotion  in 
favour  of  continuing  life  at  any  cost,  because  this  is  neces- 
sary for  the  species  ;  but  it  has  developed  no  emotion  of 
distress  on  the  extinction  of  child-mind,  because  that 
emotion  would  be  superfluous  and  unnecessary  for  the  species. 
The  subject  of  the  desirableness  of  ultimate  annihilation 
falls,  however,  outside  the  province  of  this  book. 

It  remains  now  to  summarize  the  conclusions  of  this 
chapter.  Sensation  is  the  only  fundamental  reality  attain- 
able, and  the  only  changes  which  it  can  undergo  are  by 
association  of  elementary  sensations  or  groups  of  sensations 
with  one  another.  From  sensation  with  association  is  built 
up  our  conception  of  the  Universe.  The  earliest  product 
of  associated  sensation  is  matter,  which  is  a  generalization 
comprising  a  number  of  separate  sensations  commonly 
associated.  Later  products  are  the  theories  and  principles 
of  the  various  sciences.  Mind  is  a  name  for  certain  elemen- 
tary and  associative  processes  occurring  in  the  nervous 
system.  All  the  processes  and  events  occurring  in  Nature 
fit  into  the  scheme  of  materialism  founded  in  physical  and 
chemical  laws.  In  other  words,  materialism  in  the  sense 
p 


210    MODERN  SCIENCE  AND  MATERIALISM 

indicated  is  a  true  philosophy.  There  are  no  existences 
of  spiritual  character  differing  from  matter.  Mind  and 
matter  are  equally  real,  but  they  are  not  made  of  different 
stuff.  Mind  is  neural  activity;  matter  is  associated  sensa- 
tion. That  is  to  say,  they  are  both  products  and  types 
of  experience.  Hence,  too,  they  are  both  equally  real.  There 
is  no  underlying  reality  more  real  than  themselves ;  this 
is  a  metaphysical  fancy.  We  reach  the  conclusions,  there- 
fore, of  realism  and  materialism.  But  since  the  common 
acceptation  of  the  word  materialism  implies  a  dualistic 
belief,  together  with  an  opposition  to  idealism,  the  theory 
might  more  correctly  be  styled  one  of  Absolute  Monism. 

What  effect  is  a  philosophical  theory  likely  to  have-  on 
human  conduct  ?  During  the  early  part  of  last  century 
it  was  a  favourite  doctrine  among  philosophers  that  self- 
interest  was  the  prime  motive  in  the  conduct  of  men — a 
doctrine  reflected  in  most  of  the  works  of  Political  Economy 
belonging  to  that  period.  Such  an  opinion  cannot  be  enter- 
tained for  a  moment.  Men  are  not  driven  by  intellect,  but 
by  passion  ;  they  are  guided,  not  by  Reason,  but  by  Faith. 
The  greatest  upheavals  of  history  illustrate  this  truth,  from 
the  time  of  the  First  Crusade  down  to  our  own  great  war. 
And  it  is  well  that  this  should  be  so.  A  world  driven  at 
every  turn  by  cold  calculations  of  personal  interest  might 
indeed  bear  the  outward  semblance  of  prosperity,  but  would 
be  dead  and  soulless  within.  And  so  it  is  that  philosophical 
theories  in  the  past,  where  they  have  touched  the  emotions 
of  mankind,  have  been  more  potent  springs  of  activity  than 
any  enactments  of  kings  or  parliaments.  Consider  only  how 
the  philosophy  of  the  Christian  religion  has  for  two 
millennia  dominated  the  activities  of  mankind.  Secular 
powers  control  the  bodies  of  men  ;  philosophic  faith  controls 
their  souls.  Philosophy  in  this  large  sense  underlies  and 
inspires  all  human  effort ;  it  lies  so  deep  down  in  human 
nature  that  it  often  is  not  even  seen  from  the  surface.  Yet 


IDEALISM  211 

with  silent  and  irresistible  power,  it  gradually  asserts  its 
absolute  and  all-embracing  authority  over  humanity.  For  it 
directs  their  passions,  and  from  their  passions  flow  their 
actions. 

We  all  know  the  evils  which  arise  when  error  enters  into 
the  enactments  of  secular  government.  How  inestimably 
more  lamentable  is  it  when  error  has  crept  into  our  very 
foundations  of  thought,  feeling  and  action.  Towards  every 
problem  in  life  our  minds  are  orientated  amiss.  Nothing 
goes  quite  as  it  should  ;  evils  are  encountered  on  every  side  ; 
devouring  dragons  rise  up  unreasonably  and  cannot  be  slain. 
For  the  cause  lies  too  deep  to  be  seen  ;  it  is  because  we  have 
lacked  the  courage  and  virility  to  extirpate  error  from  our 
philosophy.  Man  is  subjected  to  many  hardships  at  the 
hands  of  Nature  ;  but  they  are  as  nothing  by  comparison 
with  those  which  he  creates  for  himself  by  his  own  mis- 
directed passions.  Let  us  see  to  it  then  above  all  other 
things  that  our  philosophy  of  life  is  true.  Passion  is  the 
master :  Faith,  not  Reason,  will  for  ever  regulate  the  conduct 
of  mankind.  The  evils  which  we  make  for  ourselves  will 
only  fall  away  under  the  subtle  but  all-embracing  influence 
of  a  true  Faith. 


PRINTED   IN    GRBAT    BRITAIN    BY 
RICHARD  CLAY  &  SONS,   LIMITED, 

BRUNSWICK  ST.,  STAMFORD  ST.,  S.K.  1, 
AND  BUNOAT,   SUFFOLK. 


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